WorldWideScience

Sample records for biota nutrient cycling

  1. Nutrient cycling strategies.

    NARCIS (Netherlands)

    Breemen, van N.

    1995-01-01

    This paper briefly reviews pathways by which plants can influence the nutrient cycle, and thereby the nutrient supply of themselves and of their competitors. Higher or lower internal nutrient use efficiency positively feeds back into the nutrient cycle, and helps to increase or decrease soil

  2. Plant community development is affected by nutrients and soil biota

    NARCIS (Netherlands)

    De Deyn, G.B.; Raaijmakers, C.E.; Van der Putten, W.H.

    2004-01-01

    1 Plant community development depends to a great extent on the availability of soil nutrients, but recent studies underline the role of symbiotic, herbivorous and pathogenic soil biota. We tested for interactions between these biotic and abiotic factors by studying the effects of additional

  3. Impact of arbuscular mycorrhizal fungi on nutrient cycling in agroecosystems

    NARCIS (Netherlands)

    Köhl, L.

    2016-01-01

    The intensification of agricultural production to meet global food demands has led to excessive nutrient leaching from agricultural areas. These losses have negative environmental impacts and pose a waste of valuable fertilizer. Soil biota are essential for nutrient cycling in soil and thus could be

  4. Soil biota enhance agricultural sustainability by improving crop yield, nutrient uptake and reducing nitrogen leaching losses

    NARCIS (Netherlands)

    Bender, S.F.; van der Heijden, M.G.A.|info:eu-repo/dai/nl/240923901

    2015-01-01

    Efficient resource use is a key factor for sustainable production and a necessity for meeting future global food demands. However, the factors that control resource use efficiency in agro-ecosystems are only partly understood. We investigated the influence of soil biota on nutrient leaching,

  5. Managing Soil Biota-Mediated Decomposition and Nutrient Mineralization in Sustainable Agroecosystems

    Directory of Open Access Journals (Sweden)

    Joann K. Whalen

    2014-01-01

    Full Text Available Transformation of organic residues into plant-available nutrients occurs through decomposition and mineralization and is mediated by saprophytic microorganisms and fauna. Of particular interest is the recycling of the essential plant elements—N, P, and S—contained in organic residues. If organic residues can supply sufficient nutrients during crop growth, a reduction in fertilizer use is possible. The challenge is synchronizing nutrient release from organic residues with crop nutrient demands throughout the growing season. This paper presents a conceptual model describing the pattern of nutrient release from organic residues in relation to crop nutrient uptake. Next, it explores experimental approaches to measure the physical, chemical, and biological barriers to decomposition and nutrient mineralization. Methods are proposed to determine the rates of decomposition and nutrient release from organic residues. Practically, this information can be used by agricultural producers to determine if plant-available nutrient supply is sufficient to meet crop demands at key growth stages or whether additional fertilizer is needed. Finally, agronomic practices that control the rate of soil biota-mediated decomposition and mineralization, as well as those that facilitate uptake of plant-available nutrients, are identified. Increasing reliance on soil biological activity could benefit crop nutrition and health in sustainable agroecosystems.

  6. Stratified distribution of nutrients and extremophile biota within freshwater ice covering the surface of Lake Baikal.

    Science.gov (United States)

    Bondarenko, Nina A; Belykh, Olga I; Golobokova, Ludmila P; Artemyeva, Olga V; Logacheva, Natalia F; Tikhonova, Irina V; Lipko, Irina A; Kostornova, Tatyana Ya; Parfenova, Valentina V; Khodzher, Tamara V; Ahn, Tae-Seok; Zo, Young-Gun

    2012-02-01

    Biological entities and gradients of selected chemicals within the seemingly barren ice layers covering Lake Baikal were investigated. Ice cores 40-68 cm long were obtained from in shore and offshore sites of Southern Lake Baikal during the cold period of a year (March-April) in 2007 and 2008. In microscopic observations of the melted ice, both algae and bacteria were found in considerable numbers (>10(3) cells/L and >10(4) cells/ml, respectively). Among all organisms found, diatom was generally the most predominant taxon in the ice. Interestingly, both planktonic and benthic algae were present in considerable numbers (2-4×10(4) cells/L). Dominant phototrophic picoplankton were comprised of small green algae of various taxa and cyanobacteria of Synechococcus and Cyanobium. The bacterial community consisted mostly of short rod and cocci cells, either free-living or aggregated. Large numbers of yeast-like cells and actinomycete mycelium were also observed. Concentrations of silica, phosphorus, and nitrate were low by an order of magnitude where biota was abundant. The profile of the ice could be interpreted as vertical stratification of nutrients and biomass due to biological activities. Therefore, the organisms in the ice were regarded to maintain high activity while thriving under freezing conditions. Based on the results, it was concluded that the freshwater ice covering the surface of Lake Baikal is considerably populated by extremophilic microorganisms that actively metabolize and form a detritus food chain in the unique large freshwater ecosystem of Lake Baikal.

  7. Nutrient balances in the forest energy cycle

    International Nuclear Information System (INIS)

    Olsson, Bengt

    2006-02-01

    In Sweden, recycling of stabilised wood-ashes to forests is considered to compensate for nutrient removals from whole-tree harvesting (i.e. use of harvest residues - slash - for energy purposes). This study has analysed nutrient fluxes through the complete forest energy cycle and estimated mass balances of nutrients in harvested biomass with those in ashes, to investigate the realism in large-scale nutrient compensation with wood-ash. Expected nutrient fluxes from forests through energy plants were calculated based on nutrient and biomass data of forest stands in the Nordic countries, and from data on nutrient fluxes through CFB-plants. The expected stoichiometric composition of wood-ashes was compared with the composition of CFB-fly ashes from various Swedish energy plants. Nutrient contents for different tree fractions were calculated to express the average nutrient concentrations in slash and stems with bark, respectively. A nutrient budget synthesis of the effects of whole-tree harvesting on base cation turnover in the following stand was presented for two experimental sites. Major conclusions from the study are: In the CFB-scenario, where the bottom ash is deposited and only the fly ash can be applied to forests, the fly ash from the slash do not meet the demands for nutrient compensation for slash harvesting. Stem material (50% wood, 50% bark) must be added at equivalent amounts, as the slash to produce the amounts of fly ash needed for compensation of slash harvesting. In the scenario where more stem material was added (75% of total fuel load), the amounts of fly ashes produced hardly compensated for nutrient removals with both stem and slash harvesting. The level of nutrient compensation was lowest for potassium. The stoichiometric nutrient composition of CFB-fly ashes from Swedish energy plants is not similar with the nutrient composition of tree biomass. The higher Ca/P ratio in ashes is only partly explained by the mixture of fuels (e.g. increasing bark

  8. Changes in nitrogen isotope ratios in estuarine biota following nutrient reductions to Narragansett Bay

    Science.gov (United States)

    Increased nutrient inputs globally have resulted in widespread eutrophication to many coastal water bodies including Narragansett Bay. Efforts to reduce point source nitrogen load¬ings from waste water treatment facilities (WWTFs) and combined sewer overflows (CSOs) started i...

  9. Forest management and nutrient cycling in eastern hardwoods

    Science.gov (United States)

    James H. Patric; David W. Smith

    1975-01-01

    The literature was reviewed for reports on nutrient cycling in the eastern deciduous forest, particularly with respect to nitrogen, and for effects of forest management on the nutrient cycle. Although most such research has dealt with conifers, a considerable body of literature relates to hardwoods. Usually, only those references that dealt quantitatively with nutrient...

  10. Nutrient cycle benchmarks for earth system land model

    Science.gov (United States)

    Zhu, Q.; Riley, W. J.; Tang, J.; Zhao, L.

    2017-12-01

    Projecting future biosphere-climate feedbacks using Earth system models (ESMs) relies heavily on robust modeling of land surface carbon dynamics. More importantly, soil nutrient (particularly, nitrogen (N) and phosphorus (P)) dynamics strongly modulate carbon dynamics, such as plant sequestration of atmospheric CO2. Prevailing ESM land models all consider nitrogen as a potentially limiting nutrient, and several consider phosphorus. However, including nutrient cycle processes in ESM land models potentially introduces large uncertainties that could be identified and addressed by improved observational constraints. We describe the development of two nutrient cycle benchmarks for ESM land models: (1) nutrient partitioning between plants and soil microbes inferred from 15N and 33P tracers studies and (2) nutrient limitation effects on carbon cycle informed by long-term fertilization experiments. We used these benchmarks to evaluate critical hypotheses regarding nutrient cycling and their representation in ESMs. We found that a mechanistic representation of plant-microbe nutrient competition based on relevant functional traits best reproduced observed plant-microbe nutrient partitioning. We also found that for multiple-nutrient models (i.e., N and P), application of Liebig's law of the minimum is often inaccurate. Rather, the Multiple Nutrient Limitation (MNL) concept better reproduces observed carbon-nutrient interactions.

  11. Strong hydrological control on nutrient cycling of subtropical rainforests

    Science.gov (United States)

    Lin, T. C.; Chang, C. T.; Huang, J. C.; Wang, L.; Lin, N. H.

    2016-12-01

    Forest nutrient cycling is strongly controlled by both biological and hydrological factors. However, based on a close examination of earlier reports, we highlight the role of hydrological control on nutrient cycling at a global scale and is more important at humid tropical and subtropical forests. we analyzed the nutrient budget of precipitation input and stream water output from 1994 to 2013 in a subtropical forest in Taiwan and conducted a data synthesis using results from 32 forests across the globe. The results revealed that monthly input and output of ions were positively correlated with water quantity, indicating hydrological control on nutrient cycling. Hydrological control is also evident from the greater ions export via stream water during the warm and wet growing season. The synthesis also illustrates that strong hydrological control leads to lower nitrogen retention and greater net loss of base cations in humid regions, particularly in the humid tropical and subtropical forests. Our result is of great significance in an era of global climate change because climate change could directly affect ecosystem nutrient cycling particularly in the tropics through changes in patterns of precipitation regime.

  12. Hydromorphological control of nutrient cycling in complex river floodplain systems

    Science.gov (United States)

    Hein, T.; Bondar-Kunze, E.; Felkl, M.; Habersack, H.; Mair, M.; Pinay, G.; Tritthart, M.; Welti, N.

    2009-04-01

    Riparian zones and floodplains are key components within river ecosystems controlling nutrient cycling by promoting transformation processes and thus, act as biogeochemical hot spots. The intensity of these processes depends on the exchange conditions (the connectivity) with the main channel and the morphological setting of the water bodies. At the landscape scale, three interrelated principles of hydromorphological dynamics can be formulated regarding the cycling and transfer of carbon and nutrients in large rivers ecosystems: a) The mode of carbon and nutrient delivery affects ecosystem functioning; b) Increasing residence time and contact area impact nutrient transformation; c) Floods and droughts are natural events that strongly influence pathways of carbon and nutrient cycling. These three principles of hydromorphological dynamics control the nutrient uptake and retention and are linked over different temporal and spatial scales. All three factors can be strongly affected by natural disturbances or anthropogenic impacts, through a change in either the water regime or the geomorphologic setting of the river valley. Any change in natural water regimes will affect the biogeochemistry of riparian zones and floodplains as well as their ability to cycle and mitigate nutrient fluxes originating from upstream and/or upslope. Especially these areas have been altered by river regulation and land use changes over the last 200 years leading to the deterioration of the functioning of these compartments within the riverine landscape. The resulting deficits have prompted rehabilitation and restoration measures aiming to increase the spatial heterogeneity, the complexity, of these ecosystems. Yet, a more integrated approach is needed considering the present status of nutrient dynamics and the effects of restoration measures at different scales. The present paper analyses the effects of river side-arm restoration on ecosystem functions within the side-arm and highlights

  13. Recovery from disturbance requires resynchronization of ecosystem nutrient cycles.

    Science.gov (United States)

    Rastetter, E B; Yanai, R D; Thomas, R Q; Vadeboncoeur, M A; Fahey, T J; Fisk, M C; Kwiatkowski, B L; Hamburg, S P

    2013-04-01

    Nitrogen (N) and phosphorus (P) are tightly cycled in most terrestrial ecosystems, with plant uptake more than 10 times higher than the rate of supply from deposition and weathering. This near-total dependence on recycled nutrients and the stoichiometric constraints on resource use by plants and microbes mean that the two cycles have to be synchronized such that the ratio of N:P in plant uptake, litterfall, and net mineralization are nearly the same. Disturbance can disrupt this synchronization if there is a disproportionate loss of one nutrient relative to the other. We model the resynchronization of N and P cycles following harvest of a northern hardwood forest. In our simulations, nutrient loss in the harvest is small relative to postharvest losses. The low N:P ratio of harvest residue results in a preferential release of P and retention of N. The P release is in excess of plant requirements and P is lost from the active ecosystem cycle through secondary mineral formation and leaching early in succession. Because external P inputs are small, the resynchronization of the N and P cycles later in succession is achieved by a commensurate loss of N. Through succession, the ecosystem undergoes alternating periods of N limitation, then P limitation, and eventually co-limitation as the two cycles resynchronize. However, our simulations indicate that the overall rate and extent of recovery is limited by P unless a mechanism exists either to prevent the P loss early in succession (e.g., P sequestration not stoichiometrically constrained by N) or to increase the P supply to the ecosystem later in succession (e.g., biologically enhanced weathering). Our model provides a heuristic perspective from which to assess the resynchronization among tightly cycled nutrients and the effect of that resynchronization on recovery of ecosystems from disturbance.

  14. A Comparative-Study on Nutrient Cycling in Wet Heathland Ecosystems.2.Litter Decomposition and Nutrient Mineralization

    NARCIS (Netherlands)

    Berendse, F.; Bobbink, R.; Rouwenhorst, G.

    1989-01-01

    The concept of the relative nutrient requirement (L n) that was introduced in the first paper of this series is used to analyse the effects of the dominant plant population on nutrient cycling and nutrient mineralization in wet heathland ecosystems. A distinction is made between the effect that the

  15. Biomass and nutrient cycling by winter cover crops

    Directory of Open Access Journals (Sweden)

    Jana Koefender

    Full Text Available ABSTRACT Cover crops are of fundamental importance for the sustainability of the no-tillage system, to ensure soil coverage and to provide benefits for the subsequent crop. The objective of this study was to evaluate the production of biomass and the content and accumulation of nutrients by winter cover crops. The experimental design used in the experiment was a randomized complete block with four replications and six treatments: oilseed radish, vetch, black oats, vetch + black oats, vetch + oilseed radish and fallow. Black oat, oilseed radish in single cultivation and black oat + vetch and vetch + oilseed radish intercroppings showed higher dry matter production. Vetch + oilseed radish intercropping demonstrates higher performance regarding cycling of nutrients, with higher accumulations of N, P, K, Ca, Mg, S, Cu, Zn, Fe, Na and B.

  16. A comparative study on nutrient cycling in wet heathland ecosystems : II. Litter decomposition and nutrient mineralization.

    Science.gov (United States)

    Berendse, Frank; Bobbink, Roland; Rouwenhorst, Gerrit

    1989-03-01

    The concept of the relative nutrient requirement (L n ) that was introduced in the first paper of this series is used to analyse the effects of the dominant plant population on nutrient cycling and nutrient mineralization in wet heathland ecosystems. A distinction is made between the effect that the dominant plant species has on (1) the distribution of nutrients over the plant biomass and the soil compartment of the ecosystem and (2) the recirculation rate of nutrients. The first effect of the dominant plant species can be calculated on the basis of the δ/k ratio (which is the ratio of the relative mortality to the decomposition constant). The second effect can be analysed using the relative nutrient requirement (L n ). The mass loss and the changes in the amounts of N and P in decomposing above-ground and below-ground litter produced by Erica tetralix and Molinia caerulea were measured over three years. The rates of mass loss from both above-ground and below-ground litter of Molinia were higher than those from Erica litter. After an initial leaching phase, litter showed either a net release or a net immobilization of nitrogen or phosphorus that depended on the initial concentrations of these nutrients. At the same sites, mineralization of nitrogen and phosphorus were measured for two years both in communities dominated by Molinia and in communities dominated by Erica. There were no clear differences in the nitrogen mineralization, but in one of the two years, phosphate mineralization in the Molinia-community was significantly higher. On the basis of the theory that was developed, mineralization rates and ratios between amounts of nutrients in plant biomass and in the soil were calculated on the basis of parameters that were independently measured. There was a reasonable agreement between predicted and measured values in the Erica-communities. In the Molinia-communities there were large differences between calculated and measured values, which was explained by the

  17. Productivity and nutrient cycling in bioenergy cropping systems

    Science.gov (United States)

    Heggenstaller, Andrew Howard

    One of the greatest obstacles confronting large-scale biomass production for energy applications is the development of cropping systems that balance the need for increased productive capacity with the maintenance of other critical ecosystem functions including nutrient cycling and retention. To address questions of productivity and nutrient dynamics in bioenergy cropping systems, we conducted two sets of field experiments during 2005-2007, investigating annual and perennial cropping systems designed to generate biomass energy feedstocks. In the first experiment we evaluated productivity and crop and soil nutrient dynamics in three prototypical bioenergy double-crop systems, and in a conventionally managed sole-crop corn system. Double-cropping systems included fall-seeded forage triticale (x Triticosecale Wittmack), succeeded by one of three summer-adapted crops: corn (Zea mays L.), sorghum-sudangrass [Sorghum bicolor (L.) Moench], or sunn hemp (Crotalaria juncea L.). Total dry matter production was greater for triticale/corn and triticale/sorghum-sudangrass compared to sole-crop corn. Functional growth analysis revealed that photosynthetic duration was more important than photosynthetic efficiency in determining biomass productivity of sole-crop corn and double-crop triticale/corn, and that greater yield in the tiritcale/corn system was the outcome of photosynthesis occurring over an extended duration. Increased growth duration in double-crop systems was also associated with reductions in potentially leachable soil nitrogen relative to sole-crop corn. However, nutrient removal in harvested biomass was also greater in the double-crop systems, indicating that over the long-term, double-cropping would mandate increased fertilizer inputs. In a second experiment we assessed the effects of N fertilization on biomass and nutrient partitioning between aboveground and belowground crop components, and on carbon storage by four perennial, warm-season grasses: big bluestem

  18. Modelling nutrient cycling in forest ecosystems; Modellering av naeringssyklus i skogoekosystemer

    Energy Technology Data Exchange (ETDEWEB)

    Kvindesland, Sheila H.S.B.

    1997-12-31

    Acid deposition`s threat to fresh water and forest environments became an issue in the late 1960s. Acid deposition and forest nutrient cycling then began to be researched in greater co-operation. This thesis studies nutrient cycling processes in Norway spruce forests, emphasizing the effects on soil chemical properties, soil solution chemistry and streamwater chemistry. It investigates the effects of different aged stands on nutrient cycling and sets up nutrient budgets of the base cations and nitrogen at two sites in Norway. It also selects, documents, calibrates, tests and improves nutrient cycling models for use in Norwegian forests. 84 refs., 44 figs., 46 tabs.

  19. Influence of soil structure on nutrient cycling using microfluidic techniques

    Science.gov (United States)

    Arellano Caicedo, Carlos; Aleklett, Kristin; Ohlsson, Pelle; Hammer, Edith

    2017-04-01

    The rising of atmospheric CO2 levels and its effects on global warming make it necessary to understand the elements that regulate such levels and furthermore try to slow down the CO2 accumulation in the atmosphere. The exchange of carbon between soil and atmosphere plays a significant role in the atmospheric carbon budget. Soil organisms deposit organic compounds on and in soil aggregates, either as exudates or dead remains. Much of this dead organic material is quickly recycled, but a portion, however, will stay in the soil for long term. Evidence suggests that micro-scale biogeochemical interactions could play a highly significant role in degradation or persistence of organic matter in soils, thus, soil physical structure might play a decisive role in preventing accessibility of nutrients to microorganisms. For studying effects of spatial microstructure on soil nutrient cycles, we have constructed artificial habitats for microbes that simulate soil structures. Microfluidic, so called Lab-on-a-chip technologies, are one of the tools used to achieve our purpose. Such micro-habitats consist of pillar structures of difference density and surface area, tunnels with increasing depth, and mazes of increasing complexity to simulate different stages of soil aggregation. Using microscopy and analytical chemistry, we can follow the growth of microorganisms inoculated into the "soil chip" as well as the chemical degradation of organic matter compounds provided as nutrient source. In this way, we want to be able to predict how soil structure influences soil microbial activity leading to different effects on the carbon cycle. Our first results of a chip inoculated with natural soil showed a succession of organisms colonizing channels leading to dead-end arenas, starting with a high presence of bacteria inside the chip during the first days. Fungal hyphae growth gradually inside the channels until it finally occupied the big majority of the spaces isolating bacteria which

  20. Mass-Balance Constraints on Nutrient Cycling in Tropical Seagrass Beds

    NARCIS (Netherlands)

    Erftemeijer, P.L.A.; Middelburg, J.J.

    1995-01-01

    A relatively simple mass balance model is presented to study the cycling of nutrients (nitrogen and phosphorus) in tropical seagrass beds. The model is based on quantitative data on nutrient availability, seagrass primary production, community oxygen metabolism, seagrass tissue nutrient contents,

  1. Nutrient Cycling in Primary, Secondary Forests and Cocoa ...

    African Journals Online (AJOL)

    USER

    Abstract. Primary forest (reserved area), secondary forest and cocoa plantation land uses characterize uplands of Dwinyama watershed in Ghana within the dry semi-deciduous forest zone. The nutrients recycled in the land uses were studied through leaf litter fall, nutrient release, nutrient fluxes estimation and topsoil ...

  2. The elusive role of soil quality in nutrient cycling: a review

    NARCIS (Netherlands)

    Schroder, Jaap; Schulte, R.P.O.; Creamer, R.E.; Delgado, A.; Leeuwen, Van J.; Lehtinen, T.; Rutgers, M.; Spiegel, H.; Staes, J.; Tóth, G.; Wall, D.P.

    2016-01-01

    Cycling of nutrients, including nitrogen and phosphorus, is one of the ecosystem services we expect agricultural soils to deliver. Nutrient cycling incorporates the reuse of agricultural, industrial and municipal organic residues that, misleadingly, are often referred to as ‘wastes’. The present

  3. Isotope-aided studies of nutrient cycling and soil fertility assessment in humid pasture systems

    International Nuclear Information System (INIS)

    Wilkinson, S.R.

    1983-01-01

    Maintenance of primary productivity in grazed ecosystems depends on the orderly cycling of mineral nutrients. Potential applications of nuclear techniques to the study of soil fertility assessment and nutrient cycling are discussed for the plant nutrients N, P, K and S. The bioavailability of extrinsic and intrinsic sources of mineral nutrients are also discussed. With improvements in analytical technology, it appears feasible to use 15 N in grazed pasture ecosystems for N cycling studies. Sulphur cycling in soil/plant/grazing animal systems has been successfully studied, and further opportunities exist using 35 S to study nutrient flows in grazed grassland systems. Opportunities also appear for increased application of tracer technology in the evaluation of mineral intakes and mineral bioavailability to ruminants grazing semi-arid grassland herbage under native soil fertility, with supplemental fertilization, and in the evaluation of mineral supplementation procedures. Root system distribution and function also can be studied advantageously using tracer techniques. (author)

  4. Does diet influence consumer nutrient cycling? Macroinvertebrate and fish excretion in streams

    Science.gov (United States)

    Ryan McManamay; Jackson Webster; H. Valett; C. Dolloff

    2011-01-01

    Consumer nutrient cycling supplies limiting elements to autotrophic and heterotrophic organisms in aquatic systems. However, the role of consumers in supplying nutrients may change depending on their diet and their own stoichiometry. We evaluated the stoichiometry, N and P excretion, and diets of the dominant macroinvertebrates and fish at 6 stream sites to determine...

  5. Nutrient cycling in primary, secondary forests and cocoa plantation ...

    African Journals Online (AJOL)

    Less leaf litter production and high rainfall regimes in South America and southeast Asia probably contributed to the lower annual nutrient fluxes recorded than that of the dry semi-deciduous tropical forest in Ghana. The soil under cocoa plantation was higher in Ca than in the secondary and primary forests soils.

  6. Closing the water and nutrient cycles in soilless cultivation systems

    NARCIS (Netherlands)

    Beerling, E.A.M.; Blok, C.; Maas, van der A.A.; Os, van E.A.

    2014-01-01

    Soilless cultivation systems are common in Dutch greenhouse horticulture, i.e., less than 20% of the greenhouse area is still soil grown. For long, it was assumed that in these so-called closed systems the emission of nutrients and plant protection products (PPPs) was close to zero. However, Water

  7. Nutrient cycling in a strongly acidified mesotrophic lake

    Czech Academy of Sciences Publication Activity Database

    Kopáček, Jiří; Brzáková, Martina; Hejzlar, Josef; Nedoma, Jiří; Porcal, Petr; Vrba, Jaroslav

    2004-01-01

    Roč. 49, č. 4 (2004), s. 1202-1213 ISSN 0024-3590 R&D Projects: GA ČR(CZ) GA206/00/0063; GA ČR(CZ) GA206/03/1583 Institutional research plan: CEZ:AV0Z6017912 Keywords : acidification * nutrients * water chemistry Subject RIV: DA - Hydrology ; Limnology Impact factor: 3.024, year: 2004

  8. Nutrient cycling in salt marshes: An ecosystem service to reduce eutrophication

    DEFF Research Database (Denmark)

    Lillebø, A. I.; Sousa, A. I.; Flindt, M. R.

    2013-01-01

    aims to draw attention to the sequestration capacity of salt marshes for the excess of nutrients, and to evaluate the ecological services provided by salt marsh halophytes by regulating the biogeochemical cycles of nitrogen (N) and phosphorus (P). In this context, two case studies will be presented...... and sequestration in salt marshes. This chapter will thus emphasise that salt marsh halophytes have a crucial role on nutrient cycling and sequestration, providing ecological services that contribute to maintain the ecosystem health. © 2012 Nova Science Publishers, Inc. All rights reserved....... and discussed: By comparing young and mature marshes colonised by Saprtina maritima, we will evaluate their behaviour as sink or source of nutrients; By comparing two halophytes with distinct life cycles (Spartina maritima and Scirpus maritimus), we will evaluate species-specific N and P cycling...

  9. Reindeer grazing and soil nutrient cycling in boreal and tundra ecosystems

    OpenAIRE

    Stark, S. (Sari)

    2002-01-01

    Abstract In northernmost Fennoscandia, grazing by reindeer (Rangifer tarandus L.) has a substantial impact on the vegetation of boreal forests and arctic-alpine tundra heaths, which are reflected in below-ground processes, such as nutrient mineralization and soil organic matter decomposition. In the present thesis, the effects of reindeer grazing on soil nutrient cycling were studied by comparing grazed situation with an ungrazed control area in ten boreal forests a...

  10. Environmental pathways and radiological dosimetry for biota

    International Nuclear Information System (INIS)

    Blaylock, B.G.

    1997-01-01

    Radionuclides entering the environment as a result man's activities may be transported, cycled, and/or concentrated in the biotic and abiotic compartments of the ecosystem. Organisms in an environment contaminated with radioactive waste may be irradiated externally by radionuclides in air, water, vegetation, soil or sediment and internally by radionuclides accumulated within their bodies by inhalation or by direct absorption through their skin. The purpose of this paper is to examine the pathways in which biota are exposed to radioactive releases to the environment and to review the methods used to calculate radiation doses to the biota. In general, the methodology for estimating radiation doses to biota in their natural environment is better developed for aquatic biota than for terrestrial biota. The different methodologies which have been used for calculating radiation doses to aquatic biota were reviewed. If the protection of non-human biota is an issue in addressing environmental assessments of nuclear facilities, then the methodology for estimating radiation doses to biota should be improved. It is recommended that dose calculations should be simplified and standardized by developing dose conversion factors for a number of generic aquatic and terrestrial organisms. (author)

  11. Biogeochemical Cycling of Nutrients and Trace Metals in the Sediment of Haringvliet Lake: Response to Salinization

    NARCIS (Netherlands)

    Canavan, R.W.

    2006-01-01

    This thesis examines sediment redox processes associated with organic matter degradation and their impact on the cycling of nutrients (N, P) and trace metals (Cd, Co, Ni, Pb, Zn). Our study site, Haringvliet Lake, is located in the Rhine-Meuse River Delta in the southwest of The Netherlands. This

  12. The Influence of Epiphytic Lichens on the Nutrient Cycling of a Blue Oak Woodland

    Science.gov (United States)

    Johannes M. Knops; Thomas H. H. Nash III; William H. Schlesinger

    1997-01-01

    We evaluated the importance of epiphytic lichens in the nutrient cycling of a blue oak (Quercus douglasii) woodland in California. Each oak tree contained an average of 3.8 kg lichen biomass, totaling 590 kg per ha. For comparison, oak leaf biomass was 958 kg per ha. We compared tree growth, volume and composition of throughfall (rainfall falling...

  13. Bivalve grazing, nutrient cycling and phytoplankton dynamics in an estuarine ecosystem

    NARCIS (Netherlands)

    Prins, T.C.

    1996-01-01


    This thesis has considered the impact of the suspension feeding bivalve Mytilusedulis on nutrient cycling and phytoplankton in an estuarine ecosystem. The research was started within the framework of an extensive research project with the

  14. Interactions between plant growth and soil nutrient cycling under elevated CO2: a meta-analysis

    NARCIS (Netherlands)

    Graaff, de M.A.; Groenigen, van K.J.; Six, J.; Hungate, B.; Kessel, van C.

    2006-01-01

    free air carbon dioxide enrichment (FACE) and open top chamber (OTC) studies are valuable tools for evaluating the impact of elevated atmospheric CO2 on nutrient cycling in terrestrial ecosystems. Using meta-analytic techniques, we summarized the results of 117 studies on plant biomass production,

  15. Effects of Fallow Genealogical Cycles on the Build-up of Nutrients in ...

    African Journals Online (AJOL)

    The study examined the effect of fallow generational cycles on the buildup of nutrients in the soil. Fallow sequence of 1st, 2nd, 3rd, 4th and 5th generations were studied. The quadrat approach of sampling was employed to collect soil samples (surface and subsurface) from five plots of 10m x 10m across the five fallow ...

  16. The global carbon cycle change: Le Chatelier principle in the response of biota to changing CO2 concentration in the atmosphere

    International Nuclear Information System (INIS)

    Gorshkov, V.G.; Sherman, S.G.; Kondratyev, K.Y.

    1990-01-01

    The long-term existence of natural biota in the environment means that such a system is stable with respect to external disturbances. This system must follow the Le Chatelier principle which is based on the processes that compensate the disturbing effects. The use of the Le Chatelier principle makes it possible to choose between contradictory observational data. Available observational data on variations of the concentration of rare carbon isotopes in various media show that the oceanic biota follows the Le Chatelier principle and absorbs about half the carbon which the ocean gets from the atmosphere, compensating an increment of carbon in the atmosphere caused by an anthropogenic impact. The strongly anthropogenetically disturbed land biota does not follow the Le Chatelier principle, starting from the middle of this century. The land biota not only cannot absorb excess carbon accumulated in the atmosphere: it ejects carbon to the atmosphere in quantities equal to halved emission of carbon through fossil fuel burning. All the quantitative results considered in this paper have been obtained without using models of the biota and of the ocean

  17. Aluminum sulfate (alum) application interactions with coupled metal and nutrient cycling in a hypereutrophic lake ecosystem.

    Science.gov (United States)

    Nogaro, Geraldine; Burgin, Amy J; Schoepfer, Valerie A; Konkler, Matthew J; Bowman, Katlin L; Hammerschmidt, Chad R

    2013-05-01

    Many lake ecosystems worldwide experience severe eutrophication and associated harmful blooms of cyanobacteria due to high loadings of phosphorus (P). While aluminum sulfate (alum) has been used for decades as chemical treatment of eutrophic waters, the ecological effects of alum on coupled metal and nutrient cycling are not well known. The objective of our study was to investigate the effects of an in-situ alum treatment on aluminum and nutrient (P, N, and S) cycling in a hypereutrophic lake ecosystem. Our results indicate that the addition of alum along with sodium aluminate (as a buffer) increased dissolved aluminum and sulfate in the surface and pore waters, and altered nitrogen cycling by increasing nitrous oxide (N2O) concentrations in the surface water. The increase of aluminum and sulfate may potentially feedback to alter benthic community dynamics. These results enhance our understanding of the unintended ecological consequences of alum treatments in hypereutrophic freshwater ecosystems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. ANAEROBIC DIGESTION OF ANIMAL MANURE – IMPLICATIONS FOR CROP YIELDS AND SOIL BIOTA IN ORGANIC FARMING

    DEFF Research Database (Denmark)

    Johansen, Anders; Pommeresche, Reidun; Riely, Hugh

    2015-01-01

    of digestates affects crop yields, soil characteristics and soil biota (earthworms, springtails, microbiota). The grass-clover system showed comparable yield levels over 3 years when digested slurry was compared to untreated slurry. Digested slurries had no influence on soil nutrient concentrations or on soil......Anaerobic digestion of farmyard manures may help farmers to produce bioenergy instead of using fossil fuels, support cycling of nutrients and reduce greenhouse gas emission. However, compared to pristine slurry, digested slurry has a reduced content of organic carbon which may impact the soil biota...... organic matter levels over the first 2 years. Application of high levels of manure increased the mortality of both surface-dwelling and soil-living earthworms just after application, but the long-term effect of manure application seemed more positive, especially at low application levels. Springtails...

  19. Resuspension and estuarine nutrient cycling: insights from the Neuse River Estuary

    Directory of Open Access Journals (Sweden)

    D. R. Corbett

    2010-10-01

    Full Text Available For at least the past several decades, North Carolina's Neuse River Estuary (NRE has been subject to water quality problems relating to increased eutrophication. Research initiated in the past several years have addressed the nutrient processes of the water column and the passive diffusion processes of the benthic sedimentary environment. Resuspension of bottom sediments, by bioturbation, tides, or winds, may also have a significant effect on the flux of nutrients in an estuarine system These processes can result in the advective transport of sediment porewater, rich with nitrogen, phosphorus and carbon, into the water column. Thus, estimates of nutrient and carbon inputs from the sediments may be too low.

    This study focused on the potential change in bottom water nutrient concentrations associated with measured resuspension events. Previous research used short-lived radionuclides and meteorological data to characterize the sediment dynamics of the benthic system of the estuary. These techniques in conjunction with the presented porewater inventories allowed evaluation of the depth to which sediments have been disturbed and the advective flux of nutrients to the water column. The largest removal episode occurred in the lower NRE as the result of a wind event and was estimated that the top 2.2 cm of sediment and corresponding porewater were removed. NH4+ advective flux (resuspended was 2 to 6 times greater than simply diffusion. Phosphate fluxes were estimated to be 15 times greater than the benthic diffusive flux. Bottom water conditions with elevated NH4+ and PO43− indicate that nutrients stored in the sediments continue to play an important role in overall water quality and this study suggests that the advective flux of nutrients to the water column is critical to understand estuarine nutrient cycling.

  20. Life cycle assessment and nutrient analysis of various processing pathways in algal biofuel production.

    Science.gov (United States)

    Mu, Dongyan; Ruan, Roger; Addy, Min; Mack, Sarah; Chen, Paul; Zhou, Yong

    2017-04-01

    This study focuses on analyzing nutrient distributions and environmental impacts of nutrient recycling, reusing, and discharging in algal biofuels production. The three biomass conversion pathways compared in this study were: hydrothermal liquefaction technology (HTL), hydrothermal hydrolysis pretreatment +HTL (HTP), and wet lipid extraction (WLE). Carbon, nitrogen, and phosphorous (C, N, P) flows were described in each pathway. A primary cost analysis was conducted to evaluate the economic performance. The LCA results show that the HTP reduced life cycle NO x emissions by 10% from HTL, but increased fossil fuel use, greenhouse gas emissions, and eutrophication potential by 14%, 5%, and 28% respectively. The cost of per gallon biodiesel produced in HTP was less than in HTL. To further reduce emissions, efforts should be focused on improving nutrient uptake rates in algae cultivation, increasing biomass carbon detention in hydrothermal hydrolysis, and/or enhancing biomass conversion rates in the biooil upgrading processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Effects of mountain tea plantations on nutrient cycling at upstream watersheds

    Science.gov (United States)

    Lin, T.-C.; Shaner, P.-J. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

    2015-11-01

    The expansion of agriculture to rugged mountains can exacerbate negative impacts of agricultural activities on ecosystem function. In this study, we monitored streamwater and rainfall chemistry of mountain watersheds at the Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportion of tea plantation cover, the higher the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater of the four mountain watersheds examined; on the other hand, the concentrations of the ions that are rich in soils (SO42-, Ca2+, Mg2+) did not increase with the proportion of tea plantation cover, suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. Of the two watersheds for which rainfall chemistry was available, the one with higher proportion of tea plantation cover had higher concentrations of ions in rainfall and retained less nitrogen in proportion to input compared to the more pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. As expected, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of NO3- in streamwater by more than 70 %, indicating that such a landscape configuration helps mitigate nutrient enrichment in aquatic systems even for watersheds with steep topography. We estimated that tea plantation at our study site contributed approximately 450 kg ha-1 yr-1 of NO3-N via streamwater, an order of magnitude greater than previously reported for agricultural lands around the globe, which can only be matched by areas under intense fertilizer use. Furthermore, we constructed watershed N fluxes to show that excessive leaching of N, and additional loss to the atmosphere via volatilization and denitrification can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of

  2. Ecosystem Service of Shade Trees on Nutrient Cycling and Productivity of Coffee Agro-ecosystems

    OpenAIRE

    Rusdi Evizal; Tohari Tohari; Irfan D. Prijambada; Jaka Widada; Donny Widianto

    2009-01-01

    Shade trees are significant in certification scheme of sustainable coffee production. They play an importance role on ecosystem functioning. This research is aimed to study ecosystem service of shade trees in some coffee agro-ecosystems particularly on nutrient cycling and land productivity. Four agro-ecosys tems of Robusta coffee (Coffea canephora), namely sun coffee (without shade trees), coffee shaded by Michelia champaca, coffee shaded by Gliricidia sepium, and coffee shaded by Erythrina ...

  3. Ecosystem Service of Shade Trees on Nutrient Cycling and Productivity of Coffee Agro-ecosystems

    Directory of Open Access Journals (Sweden)

    Rusdi Evizal

    2009-05-01

    Full Text Available Shade trees are significant in certification scheme of sustainable coffee production. They play an importance role on ecosystem functioning. This research is aimed to study ecosystem service of shade trees in some coffee agro-ecosystems particularly on nutrient cycling and land productivity. Four agro-ecosys tems of Robusta coffee (Coffea canephora, namely sun coffee (without shade trees, coffee shaded by Michelia champaca, coffee shaded by Gliricidia sepium, and coffee shaded by Erythrina indica are evaluated during 2007—2008. Smallholder coffee plantation in Sumberjaya Subdistrict, West Lampung, which managed under local standard were employed using Randomized Complete Block Design with 3 replications. The result showed that litter fall dynamic from shade trees and from coffee trees was influenced by rainfall. Shade trees decreased weed biomass while increased litter fall production. In dry season, shade trees decreased litter fall from coffee shaded by M. champaca. G. sepium and E. indica shaded coffee showed higher yield than sun coffee and M. champaca shaded coffee. Except for M. champaca shaded coffee, yield had positive correlation (r = 0.99 with litter fall production and had negative correlation (r = —0.82 with weed biomass production. Biomass production (litter fall + weed of sun coffee and shaded coffee was not significantly different. Litter fall of shade trees had significance on nutrient cycle mainly to balance the lost of nitrogen in coffee bean harvesting.Key Words: Coffea canephora, Michelia champaca, Gliricidia sepium, Erythrina indica, litter production, nutrient cycle, coffee yield.

  4. The microbial perspective of organic matter turnover and nutrient cycling in tropical soils

    Science.gov (United States)

    Rasche, Frank

    2017-04-01

    A primary goal of low-input small-holder farming systems in the tropics is the appropriate management of organic matter (OM) turnover and nutrient cycling via adapted agricultural practices. These emphasize the promotion of soil organic matter (SOM) turnover and carbon (C) sequestration, nutrient use efficiency and soil microbial activity. Since soil microbial communities are acknowledged as key players in the terrestrial C and nutrient (e.g., nitrogen (N), phosphorus (P)) cycles, they may respond sensitively to agricultural management with shifts in their community structure as well as functional traits (i.e., decomposition, mineralization). This may be in particular evident for tropical, agricultural soils which show an accelerated microbial decomposition activity induced by favourable climatic and unique physico-chemical soil conditions. While modern molecular techniques advanced primarily the understanding about the microbiome and their functional traits interacting closely with SOM dynamics in temperate soils, tropical soils under agricultural use have been still neglected to a great extent. The majority of available studies revealed mainly descriptive data on the structural composition of microbial communities rather than questioning if detected structural alterations of the soil microbiome influenced key processes in N and P cycling which actually maintain ecosystem functioning and soil productivity. This talk highlights latest efforts in deploying molecular techniques to study the compositional status of soil microbial decomposer communities and their functional attributes in response to land use change and OM management in tropical agro-ecosystems.

  5. Coupled nutrient cycling determines tropical forest trajectory under elevated CO2.

    Science.gov (United States)

    Bouskill, N.; Zhu, Q.; Riley, W. J.

    2017-12-01

    Tropical forests have a disproportionate capacity to affect Earth's climate relative to their areal extent. Despite covering just 12 % of land surface, tropical forests account for 35 % of global net primary productivity and are among the most significant of terrestrial carbon stores. As atmospheric CO2 concentrations increase over the next century, the capacity of tropical forests to assimilate and sequester anthropogenic CO2 depends on limitation by multiple factors, including the availability of soil nutrients. Phosphorus availability has been considered to be the primary factor limiting metabolic processes within tropical forests. However, recent evidence points towards strong spatial and temporal co-limitation of tropical forests by both nitrogen and phosphorus. Here, we use the Accelerated Climate Modeling for Energy (ACME) Land Model (ALMv1-ECA-CNP) to examine how nutrient cycles interact and affect the trajectory of the tropical forest carbon sink under, (i) external nutrient input, (ii) climate (iii) elevated CO2, and (iv) a combination of 1-3. ALMv1 includes recent theoretical advances in representing belowground competition between roots, microbes and minerals for N and P uptake, explicit interactions between the nitrogen and phosphorus cycles (e.g., phosphatase production and nitrogen fixation), the dynamic internal allocation of plant N and P resources, and the integration of global datasets of plant physiological traits. We report nutrient fertilization (N, P, N+P) predictions for four sites in the tropics (El Verde, Puerto Rico, Barro Colorado Island, Panama, Manaus, Brazil and the Osa Peninsula, Coast Rica) to short-term nutrient fertilization (N, P, N+P), and benchmarking of the model against a meta-analysis of forest fertilization experiments. Subsequent simulations focus on the interaction of the carbon, nitrogen, and phosphorus cycles across the tropics with a focus on the implications of coupled nutrient cycling and the fate of the tropical

  6. Dimensions of biodiversity of oceanic nitrogen cycling: nutrient co-limitation, nitrogen substrate preferences and more.

    Science.gov (United States)

    Zehr, J.; Mills, M. M.; Shilova, I. N.; Turk-Kubo, K.; Robidart, J.; van Dijken, G.; Bjorkman, K. M.; Whitt, D. B.; Wai, B.; Pampin Baro, J.; Hogan, M.; Rapp, I.; Zakem, E.; Fredrickson, A.; Leahy, B.; Linney, M.; Santiago, A.; Follows, M. J.; Achterberg, E. P.; Kolber, Z.; Church, M. J.; Arrigo, K. R.

    2016-02-01

    We conducted the research cruise: Nutrient Effects on Marine microOrganisms (NEMO) onboard the R/V New Horizon (NH1417: August 18 to September 16, 2014) between the ports of San Diego, CA and Honolulu, HI. The three major objectives of the cruise were to: 1) evaluate genetic, physiological and phylogenetic responses of marine phytoplankton communities in the North Pacific Subtropical Gyre to different nitrogen (N) substrates and to determine how other nutrients (iron, phosphorus) impact N utilization; 2) characterize the physical processes and dynamics in support of the biological processes; and 3) characterize the diversity and activities of microbial communities in the upper water column in relation to the nutrient availability. Several incubation experiments were conducted along the cruise transect to assess the effect of nutrients on microbial communities. The results showed that N addition resulted in increased chlorophyll a (chl a) and rates of CO2 fixation at most sites, but Prochlorococcus, Synechococcus and picoekaryotic phytoplankton had different responses to urea, ammonium and nitrate. In contrast, chl a and CO2 fixation did not respond to additions of single nutrient (e.g. N, P or Fe alone) at the westernmost experiment (151°W), where the simultaneous addition of N and P was required for stimulation. The physical dynamics were studied through high-resolution surveys of eddy dipole features as well as diel sampling at two locations. Additionally, we characterized an extensive bloom that occurred near the critical latitude (29°N, 140°W) from mid July to the end of September; a typical but still enigmatic event. Here, we present a summary of the initial observations and findings from the NEMO cruise with data including physics, nutrient concentrations, chl a, primary productivity and microbial community composition. The results of this research cruise will help in assessing how ocean N cycling and ecosystem functions will respond to global climate

  7. Applying Sewage Sludge to Eucalyptus grandis Plantations: Effects on Biomass Production and Nutrient Cycling through Litterfall

    International Nuclear Information System (INIS)

    Da Silva, P.H.M.; Poggiani, F.; Laclau, J.P.

    2011-01-01

    In most Brazilian cities sewage sludge is dumped into sanitary landfills, even though its use in forest plantations as a fertilizer and soil conditioner might be an interesting option. Sewage sludge applications might reduce the amounts of mineral fertilizers needed to sustain the productivity on infertile tropical soils. However, sewage sludge must be applied with care to crops to avoid soil and water pollution. The aim of our study was to assess the effects of dry and wet sewage sludges on the growth and nutrient cycling of Eucalyptus grandis plantations established on the most common soil type for Brazilian eucalypt plantations. Biomass production and nutrient cycling were studied over a 36-month period in a complete randomized block design. Four experimental treatments were compared: wet sewage sludge, dry sludge, mineral fertilizer, and no fertilizer applications. The two types of sludges as well as mineral fertilizer increased significantly the biomass of Eucalyptus trees. Wood biomass productions 36 months after planting were similar in the sewage sludge and mineral fertilization treatments (about 80 tons ha - '1) and 86 % higher than in the control treatment. Sewage sludge application also affected positively leaf litter production and significantly increased nutrient transfer among the components of the ecosystem.

  8. Applying Sewage Sludge to Eucalyptus grandis Plantations: Effects on Biomass Production and Nutrient Cycling through Litterfall

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Müller da Silva

    2011-01-01

    Full Text Available In most Brazilian cities sewage sludge is dumped into sanitary landfills, even though its use in forest plantations as a fertilizer and soil conditioner might be an interesting option. Sewage sludge applications might reduce the amounts of mineral fertilizers needed to sustain the productivity on infertile tropical soils. However, sewage sludge must be applied with care to crops to avoid soil and water pollution. The aim of our study was to assess the effects of dry and wet sewage sludges on the growth and nutrient cycling of Eucalyptus grandis plantations established on the most common soil type for Brazilian eucalypt plantations. Biomass production and nutrient cycling were studied over a 36-month period in a complete randomized block design. Four experimental treatments were compared: wet sewage sludge, dry sludge, mineral fertilizer, and no fertilizer applications. The two types of sludges as well as mineral fertilizer increased significantly the biomass of Eucalyptus trees. Wood biomass productions 36 months after planting were similar in the sewage sludge and mineral fertilization treatments (about 80 tons ha−1 and 86% higher than in the control treatment. Sewage sludge application also affected positively leaf litter production and significantly increased nutrient transfer among the components of the ecosystem.

  9. The biogeochemical role of baleen whales and krill in Southern Ocean nutrient cycling.

    Directory of Open Access Journals (Sweden)

    Lavenia Ratnarajah

    Full Text Available The availability of micronutrients is a key factor that affects primary productivity in High Nutrient Low Chlorophyll (HNLC regions of the Southern Ocean. Nutrient supply is governed by a range of physical, chemical and biological processes, and there are significant feedbacks within the ecosystem. It has been suggested that baleen whales form a crucial part of biogeochemical cycling processes through the consumption of nutrient-rich krill and subsequent defecation, but data on their contribution are scarce. We analysed the concentration of iron, cadmium, manganese, cobalt, copper, zinc, phosphorus and carbon in baleen whale faeces and muscle, and krill tissue using inductively coupled plasma mass spectrometry. Metal concentrations in krill tissue were between 20 thousand and 4.8 million times higher than typical Southern Ocean HNLC seawater concentrations, while whale faecal matter was between 276 thousand and 10 million times higher. These findings suggest that krill act as a mechanism for concentrating and retaining elements in the surface layer, which are subsequently released back into the ocean, once eaten by whales, through defecation. Trace metal to carbon ratios were also higher in whale faeces compared to whale muscle indicating that whales are concentrating carbon and actively defecating trace elements. Consequently, recovery of the great whales may facilitate the recycling of nutrients via defecation, which may affect productivity in HNLC areas.

  10. The biogeochemical role of baleen whales and krill in Southern Ocean nutrient cycling.

    Science.gov (United States)

    Ratnarajah, Lavenia; Bowie, Andrew R; Lannuzel, Delphine; Meiners, Klaus M; Nicol, Stephen

    2014-01-01

    The availability of micronutrients is a key factor that affects primary productivity in High Nutrient Low Chlorophyll (HNLC) regions of the Southern Ocean. Nutrient supply is governed by a range of physical, chemical and biological processes, and there are significant feedbacks within the ecosystem. It has been suggested that baleen whales form a crucial part of biogeochemical cycling processes through the consumption of nutrient-rich krill and subsequent defecation, but data on their contribution are scarce. We analysed the concentration of iron, cadmium, manganese, cobalt, copper, zinc, phosphorus and carbon in baleen whale faeces and muscle, and krill tissue using inductively coupled plasma mass spectrometry. Metal concentrations in krill tissue were between 20 thousand and 4.8 million times higher than typical Southern Ocean HNLC seawater concentrations, while whale faecal matter was between 276 thousand and 10 million times higher. These findings suggest that krill act as a mechanism for concentrating and retaining elements in the surface layer, which are subsequently released back into the ocean, once eaten by whales, through defecation. Trace metal to carbon ratios were also higher in whale faeces compared to whale muscle indicating that whales are concentrating carbon and actively defecating trace elements. Consequently, recovery of the great whales may facilitate the recycling of nutrients via defecation, which may affect productivity in HNLC areas.

  11. Environmental performance of biological nutrient removal processes from a life cycle perspective.

    Science.gov (United States)

    Ontiveros, Guillermo A; Campanella, Enrique A

    2013-12-01

    The goal of the present study is to assess different alternatives for a wastewater treatment plant module with capacity to remove nutrients biologically, taking into account present Argentine regulations for effluent discharge. A computational modeling tool (GPS-X) was employed to simulate the behavior of the different alternatives, and Life Cycle Assessment was applied to quantify the environmental impact. A 2000 m(3)/d municipal wastewater flow was used to carry out the simulations, the annual flow was utilized as functional units and the main topics analyzed were energy efficiency, land use, eutrophication reduction and biosolid reuse. Biogas and biosolid generation was evaluated as a good opportunity to generate a cleaner process. This study highlights the fact that nutrient removal processes significantly improve the quality of effluent and biosolids and reduces energy consumption. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. A mechanistic soil biogeochemistry model with explicit representation of microbial and macrofaunal activities and nutrient cycles

    Science.gov (United States)

    Fatichi, Simone; Manzoni, Stefano; Or, Dani; Paschalis, Athanasios

    2016-04-01

    The potential of a given ecosystem to store and release carbon is inherently linked to soil biogeochemical processes. These processes are deeply connected to the water, energy, and vegetation dynamics above and belowground. Recently, it has been advocated that a mechanistic representation of soil biogeochemistry require: (i) partitioning of soil organic carbon (SOC) pools according to their functional role; (ii) an explicit representation of microbial dynamics; (iii) coupling of carbon and nutrient cycles. While some of these components have been introduced in specialized models, they have been rarely implemented in terrestrial biosphere models and tested in real cases. In this study, we combine a new soil biogeochemistry model with an existing model of land-surface hydrology and vegetation dynamics (T&C). Specifically the soil biogeochemistry component explicitly separates different litter pools and distinguishes SOC in particulate, dissolved and mineral associated fractions. Extracellular enzymes and microbial pools are explicitly represented differentiating the functional roles of bacteria, saprotrophic and mycorrhizal fungi. Microbial activity depends on temperature, soil moisture and litter or SOC stoichiometry. The activity of macrofauna is also modeled. Nutrient dynamics include the cycles of nitrogen, phosphorous and potassium. The model accounts for feedbacks between nutrient limitations and plant growth as well as for plant stoichiometric flexibility. In turn, litter input is a function of the simulated vegetation dynamics. Root exudation and export to mycorrhiza are computed based on a nutrient uptake cost function. The combined model is tested to reproduce respiration dynamics and nitrogen cycle in few sites where data were available to test plausibility of results across a range of different metrics. For instance in a Swiss grassland ecosystem, fine root, bacteria, fungal and macrofaunal respiration account for 40%, 23%, 33% and 4% of total belowground

  13. Internal cycling, not external loading, decides the nutrient limitation in eutrophic lake: A dynamic model with temporal Bayesian hierarchical inference.

    Science.gov (United States)

    Wu, Zhen; Liu, Yong; Liang, Zhongyao; Wu, Sifeng; Guo, Huaicheng

    2017-06-01

    Lake eutrophication is associated with excessive anthropogenic nutrients (mainly nitrogen (N) and phosphorus (P)) and unobserved internal nutrient cycling. Despite the advances in understanding the role of external loadings, the contribution of internal nutrient cycling is still an open question. A dynamic mass-balance model was developed to simulate and measure the contributions of internal cycling and external loading. It was based on the temporal Bayesian Hierarchical Framework (BHM), where we explored the seasonal patterns in the dynamics of nutrient cycling processes and the limitation of N and P on phytoplankton growth in hyper-eutrophic Lake Dianchi, China. The dynamic patterns of the five state variables (Chla, TP, ammonia, nitrate and organic N) were simulated based on the model. Five parameters (algae growth rate, sediment exchange rate of N and P, nitrification rate and denitrification rate) were estimated based on BHM. The model provided a good fit to observations. Our model results highlighted the role of internal cycling of N and P in Lake Dianchi. The internal cycling processes contributed more than external loading to the N and P changes in the water column. Further insights into the nutrient limitation analysis indicated that the sediment exchange of P determined the P limitation. Allowing for the contribution of denitrification to N removal, N was the more limiting nutrient in most of the time, however, P was the more important nutrient for eutrophication management. For Lake Dianchi, it would not be possible to recover solely by reducing the external watershed nutrient load; the mechanisms of internal cycling should also be considered as an approach to inhibit the release of sediments and to enhance denitrification. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Representation of deforestation impacts on climate, water, and nutrient cycles in the ACME earth system model

    Science.gov (United States)

    Cai, X.; Riley, W. J.; Zhu, Q.

    2017-12-01

    Deforestation causes a series of changes to the climate, water, and nutrient cycles. Employing a state-of-the-art earth system model—ACME (Accelerated Climate Modeling for Energy), we comprehensively investigate the impacts of deforestation on these processes. We first assess the performance of the ACME Land Model (ALM) in simulating runoff, evapotranspiration, albedo, and plant productivity at 42 FLUXNET sites. The single column mode of ACME is then used to examine climate effects (temperature cooling/warming) and responses of runoff, evapotranspiration, and nutrient fluxes to deforestation. This approach separates local effects of deforestation from global circulation effects. To better understand the deforestation effects in a global context, we use the coupled (atmosphere, land, and slab ocean) mode of ACME to demonstrate the impacts of deforestation on global climate, water, and nutrient fluxes. Preliminary results showed that the land component of ACME has advantages in simulating these processes and that local deforestation has potentially large impacts on runoff and atmospheric processes.

  15. Influences of Moisture Regimes and Functional Plant Types on Nutrient Cycling in Permafrost Regions

    Science.gov (United States)

    McCaully, R. E.; Arendt, C. A.; Newman, B. D.; Heikoop, J. M.; Wilson, C. J.; Sevanto, S.; Wales, N. A.; Wullschleger, S.

    2017-12-01

    In the permafrost-dominated Arctic, climatic feedbacks exist between permafrost, soil moisture, functional plant type and presence of nutrients. Functional plant types present within the Arctic regulate and respond to changes in hydrologic regimes and nutrient cycling. Specifically, alders are a member of the birch family that use root nodules to fix nitrogen, which is a limiting nutrient strongly linked to fertilizing Arctic ecosystems. Previous investigations in the Seward Peninsula, AK show elevated presence of nitrate within and downslope of alder patches in degraded permafrost systems, with concentrations an order of magnitude greater than that of nitrate measured above these patches. Further observations within these degraded permafrost systems are crucial to assess whether alders are drivers of, or merely respond to, nitrate fluxes. In addition to vegetative feedbacks with nitrate supply, previous studies have also linked low moisture content to high nitrate production. Within discontinuous permafrost regions, the absence of permafrost creates well-drained regions with unsaturated soils whereas the presence of permafrost limits vertical drainage of soil-pore water creating elevated soil moisture content, which likely corresponds to lower nitrate concentrations. We investigate these feedbacks further in the Seward Peninsula, AK, through research supported by the United States Department of Energy Next Generation Ecosystem Experiment (NGEE) - Arctic. Using soil moisture and thaw depth as proxies to determine the extent of permafrost degradation, we identify areas of discontinuous permafrost over a heterogeneous landscape and collect co-located soilwater chemistry samples to highlight the complex relationships that exist between alder patches, soil moisture regimes, the presence of permafrost and available nitrate supply. Understanding the role of nitrogen in degrading permafrost systems, in the context of both vegetation present and soil moisture, is crucial

  16. Nutrient cycling and ecosystem metabolism in boreal streams of the Central Siberian Plateau

    Science.gov (United States)

    Diemer, L.; McDowell, W. H.; Prokushkin, A. S.

    2013-12-01

    mechanisms controlling nutrient processing and productivity in headwater streams of Central Siberia will be critical to understanding global biogeochemical cycling, particularly as these systems respond to climate change.

  17. Evergreen shrub traits and peatland carbon cycling under high nutrient load

    Science.gov (United States)

    Larmola, Tuula; Bui, Vi; Bubier, Jill L.; Wang, Meng; Murphy, Meaghan; Moore, Tim R.

    2016-04-01

    The reactive nitrogen (N) assimilated by plants is usually invested in chlorophyll to improve light harvesting capacity and in soluble proteins such as Rubisco to enhance carbon (C) assimilation. We studied the effects of simulated atmospheric N deposition on different traits of two evergreen shrubs Chamaedaphne calyculata and Rhododendron groenlandicum in a nutrient-poor Mer Bleue Bog, Canada that has been fertilized with N as NO3 and NH4 (2-8 times ambient annual wet deposition) with or without phosphorus (P) and potassium (K) for 7-12 years. We examined how nutrient addition influences the plant performance at leaf and canopy level and linked the trait responses with ecosystem C cycling. At the leaf level, we measured physiological and biochemical traits: CO2 exchange and chlorophyll fluorescence, an indicator of plant stress in terms of light harvesting capacity; and to study changes in photosynthetic nutrient use efficiency, we also determined the foliar chlorophyll, N, and P contents. At the canopy level, we examined morphological and phenological traits: growth responses and leaf longevity during two growing seasons. Regardless of treatment, the majority of leaves showed no signs of stress in terms of light harvesting capacity. The plants were N saturated: with increasing foliar N content, the higher proportion of N was not used in photosynthesis. Foliar net CO2 assimilation rates did not differ significantly among treatments, but the additions of N, P, and K together resulted in higher respiration rates. The analysis of the leaf and canopy traits showed that the two shrubs had different strategies: C. calyculata was more responsive to nutrient additions, more deciduous-like, whereas R. groenlandicum maintained evergreen features under nutrient load, shedding its leaves even later in the season. In all, simulated atmospheric N deposition did not benefit the photosynthetic apparatus of the dominant shrubs, but resulted in higher foliar respiration

  18. Biomass production and nutrient cycling in Eucalyptus short rotation energy forests in New Zealand: II. Litter fall and nutrient return

    Energy Technology Data Exchange (ETDEWEB)

    Guo, L.B.; Sims, R.E.H. [Institute of Technology and Engineering, Massey University, Private Bag 11222, Palmerston North (New Zealand); Horne, D.J. [Institute of Natural Resources, Massey University, Private Bag 11222, Palmerston North (New Zealand)

    2006-05-15

    Litter fall and nutrient return via the litter fall were measured during the first 3-yr rotation of three Eucalyptus short rotation forest species (E. botryoides, E. globulus and E. ovata) irrigated with meatworks effluent compared with no irrigation. Up to 13.4 oven-dry t/ha/yr of annual litter fall was recorded with nutrient returns of up to 159kgN/ha/yr, 9kgP/ha/yr, 28kgK/ha/yr, 125kgCa/ha/yr, 22kgMg/ha/yr, and 32kgMn/ha/yr. Effluent irrigation increased the litter fall and the return of some nutrients. More litter fall with higher nutrient return was found under E. globulus than under the other two species. However, the amounts of litter fall and nutrient return were highly dependent on the degree of biomass production and nutrient uptake. During the 3-yr period, up to 20% of the total above ground biomass produced was in the form of litter, and via the litter fall, up to 24% of the total N uptake was returned to the soil surface. (author)

  19. A Metagenomic Perspective on Changes to Nutrient-cycling Genes Following Forest-to-agriculture Conversion in the Amazon Basin

    Science.gov (United States)

    Meyer, K. M.; Womack, A. M.; Rodrigues, J.; Nüsslein, K.; Bohannan, B. J. M.

    2014-12-01

    Forest-to-agriculture conversion has been shown to alter nutrient cycling and the community composition of soil microorganisms. However, few studies have looked simultaneously at how the abundance, composition, and diversity of microbial genes involved in nutrient cycling change with conversion. We used shotgun metagenomic sequencing to analyze soil from primary rainforest and converted cattle pasture sampled at the Fazenda Nova Vida in Rondônia, Brazil. The diversity, richness, and evenness of nutrient cycling genes were significantly higher in the pasture, and the composition of nutrient cycling communities differed significantly between land use types. These results largely mirror taxonomic shifts following Amazon rainforest conversion, which tends to increase diversity, richness, and evenness of soil microbial communities. The abundance of genes related to N cycling and methane flux differed between land use types. Methanotrophy genes decreased in abundance in the pasture, whereas methanogenesis genes were not significantly different between land use types. These changes could underlie the commonly observed shift from methane sink to source following forest-to-agriculture conversion. Multiple genes in the nitrogen cycle also differed with land use, including genes related to N-fixation and ammonification. Metagenomics provides a unique perspective on the consequences of land use change on microbial community structure and function.

  20. Including Life Cycle Assessment for decision-making in controlling wastewater nutrient removal systems

    DEFF Research Database (Denmark)

    Corominas, Lluís; Larsen, Henrik Fred; Flores-Alsina, Xavier

    2013-01-01

    of the impact categories is conducted to assess how value choices (policy decisions) may affect the management of WWTPs. For the scenarios with only N-limitation, the LCA-based ranking of the control strategies is sensitive to the choice of weighting factors, whereas this is not the case for N&P or P......This paper focuses on the use of Life Cycle Assessment (LCA) to evaluate the performance of seventeen control strategies in wastewater treatment plants (WWTPs). It tackles the importance of using site-specific factors for nutrient enrichment when decision-makers have to select best operating....../or energy savings present an environmental benefit for N&P and P-deficient systems. This is not the case when addressing N-deficient systems for which the use of chemicals (even for improving N removal efficiencies) is not always beneficial for the environment. A sensitivity analysis on using weighting...

  1. Floodplain trapping and cycling compared to streambank erosion of sediment and nutrients in an agricultural watershed

    Science.gov (United States)

    Gillespie, Jaimie; Noe, Gregory; Hupp, Cliff R.; Gellis, Allen; Schenk, Edward R.

    2018-01-01

    Floodplains and streambanks can positively and negatively influence downstream water quality through interacting geomorphic and biogeochemical processes. Few studies have measured those processes in agricultural watersheds. We measured inputs (floodplain sedimentation and dissolved inorganic loading), cycling (floodplain soil nitrogen [N] and phosphorus [P] mineralization), and losses (bank erosion) of sediment, N, and P longitudinally in stream reaches of Smith Creek, an agricultural watershed in the Valley and Ridge physiographic province. All study reaches were net depositional (floodplain deposition > bank erosion), had high N and P sedimentation and loading rates to the floodplain, high soil concentrations of N and P, and high rates of floodplain soil N and P mineralization. High sediment, N, and P inputs to floodplains are attributed to agricultural activity in the region. Rates of P mineralization were much greater than those measured in other studies of nontidal floodplains that used the same method. Floodplain connectivity and sediment deposition decreased longitudinally, contrary to patterns in most watersheds. The net trapping function of Smith Creek floodplains indicates a benefit to water quality. Further research is needed to determine if future decreases in floodplain deposition, continued bank erosion, and the potential for nitrate leaching from nutrient-enriched floodplain soils could pose a long-term source of sediment and nutrients to downstream rivers.

  2. Pharmaceutical consumption and residuals potentially relevant to nutrient cycling in Greater Accra, Ghana

    Directory of Open Access Journals (Sweden)

    Evren Sinar

    2010-04-01

    Full Text Available Recycling nutrients form sanitary wastes back into agricultural ecosystems offers an option to alleviate soil depletion in regions where the use of mineral fertiliser is limited. Exemplary nutrient and water cycling approaches, including collection, treatment and use of human urine, are established at Valley View University (VVU in Greater Accra, Ghana.Concerns have been recently raised in regard to fate and impact of pharmaceutical residues in soils and interlinked environment. To evaluate in how far emerging knowledge can be transposed onto VVU, urban and rural environments in Greater Accra, spatial disease occurrence and drug consumption patterns were studied. Malaria has been found to represent the most severe health burden in Ghana, but there is also a high prevalence of infectious diseases. Drugs consumed in great quantities and in respect to their residual loads potentially problematic in the environment belong to therapeutic groups of: antibiotics, analgesics, drugs for diabetes, antimalarials, cardiovascular drugs and anthelmintics. Drug consumption revealed to be highest in urban and lowest in rural areas. At VVU the range of consumed drugs is comparable to urban areas except for the negligible use of diabetes and cardiovascular medication as well as contraceptives.

  3. Nutrient cycling, connectivity, and free-floating plant abundance in backwater lakes of the Upper Mississippi River

    Science.gov (United States)

    Houser, Jeff N.; Giblin, Shawn M.; James, William F.; Langrehr, H.A.; Rogala, James T.; Sullivan, John F.; Gray, Brian R.

    2013-01-01

    River eutrophication may cause the formation of dense surface mats of free floating plants (FFP; e.g., duckweeds and filamentous algae) which may adversely affect the ecosystem. We investigated associations among hydraulic connectivity to the channel, nutrient cycling, FFP, submersed aquatic vegetation (SAV), and dissolved oxygen concentration (DO) in ten backwater lakes of the Upper Mississippi River (UMR) that varied in connectivity to the channel. Greater connectivity was associated with higher water column nitrate (NO3-N) concentration, higher rates of sediment phosphorus (P) release, and higher rates of NO3-N flux to the sediments. Rates of sediment P and N (as NH4-N) release were similar to those of eutrophic lakes. Water column nutrient concentrations were high, and FFP tissue was nutrient rich suggesting that the eutrophic condition of the UMR often facilitated abundant FFP. However, tissue nutrient concentrations, and the associations between FFP biomass and water column nutrient concentrations, suggested that nutrients constrained FFP abundance at some sites. FFP abundance was positively associated with SAV abundance and negatively associated with dissolved oxygen concentration. These results illustrate important connections among hydraulic connectivity, nutrient cycling, FFP, SAV, and DO in the backwaters of a large, floodplain river.

  4. Paleoproductivity and Nutrient Cycling on the Sumatra Margin during the Past Half Million Years

    Science.gov (United States)

    Gibson, K.; Mitt Schwamborn, T.; Thunell, R.; Tuten, E. C.; Swink, C.; Tappa, E.

    2017-12-01

    In the IndoPacific, changes in paleoproductivity on orbital timescales are often linked to changes in precession, particularly in areas of coastal upwelling. These changes are in turn related to variations in zonal wind patterns and thermocline tilt associated with the El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), and commensurate changes in Asian, Indian, and Australian monsoon precipitation and wind-driven upwelling. Previous studies have revealed varying phase relationships amongst monsoon precipitation, upwelling variability and precession minima in the Indo-Pacific region. Regional records have additionally displayed power in the 41-kyr band, attributed to changes in deepwater ventilation and preservation, and the 100-kyr band, related to the influence of sea level on the Indonesian Throughflow (ITF). To provide further insight into the regional and distal forcing on paleoproductivity and nutrient cycling in this clearly complex region, we present %TOC, %CaCO3, and sedimentary δ15N data from core MD98-2152, off the Sumatra margin in a region influenced by both ITF variability and wind-driven upwelling. By comparing our paleoproductivity and paleonutrient data with planktonic δ18O (tuned to composite Chinese cave speleothem records) and benthic δ18O (tuned to the Lisiecki-Raymo Stack), we compare timing of local productivity changes to high latitude ice-volume changes and local hydrographic changes. A strong 23-kyr signal in the %TOC record supports the strong influence of precession on paleoproductivity in this region. In contrast, strong power in the 100 and 41-kyr bands is observed in %CaCO3 and δ15N with a relatively minor contribution from precession, indicating a complex relationship between nutrient cycling, upwelling, production, and preservation on the Sumatra coast.

  5. The soil N cycle: new insights and key challenges

    NARCIS (Netherlands)

    Groenigen, van J.W.; Huygens, D.; Boeckx, P.; Kuyper, T.W.; Lubbers, I.M.; Rutting, L.; Groffman, P.M.

    2015-01-01

    The study of soil N cycling processes has been, is, and will be at the centre of attention in soil science research. The importance of N as a nutrient for all biota; the ever-increasing rates of its anthropogenic input in terrestrial (agro)ecosystems; its resultant losses to the environment; and the

  6. Effects of repetitive droughts on carbon, nutrient and water cycles of heathland ecosystem

    Science.gov (United States)

    Rineau, Francois; Beenaerts, Natalie; Nijs, Ivan; De Boeck, Hans; Vangronsveld, Jaco

    2017-04-01

    A large body of research is now focusing on the understanding of mechanisms regulating ecosystem functioning, predictions on their activity in the long-term, and the management practices to keep them running. For this purpose, Hasselt University decided to invest in the construction of a high technological research infrastructure: the "Ecotron Hasselt University", where twelve large ecosystem replicates can be continuously monitored and controlled. The ecotrons will be fed with real-time climatic data from a nearby ICOS tower located on top of a heathland landscape. The research performed there will focus on understanding the response of heathland ecosystem services (ES) to yearly repeated droughts of different intensities. We aim to perform as well an economical valuation of these ES. From a biological point of view, we will measure soil processes that drive the three most valuable ES: water, C and nutrient cycles, and especially how soil organisms affect them, through which mechanisms and at different drought intensities. Species interactions and their influence on C sequestration and organic matter degradation will be also incorporated into a state-of-the art soil C cycling model.

  7. Biomass production and nutrient cycling in Eucalyptus short rotation energy forests in New Zealand. 1: biomass and nutrient accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Guo, L.B.; Sims, R.E.H. [Massey University, Palmerston North (New Zealand). Institute of Technology and Engineering; Horne, D.J. [Massey University, Palmerston North (New Zealand). Institute of Natural Resources

    2002-12-01

    Accumulation of biomass and nutrients (N, P, K, Ca, Mg and Mn) was measured during the first 3- year rotation of three Eucalyptus short rotation forest species (E. botryoides, E. globulus and E. ovata) irrigated with meatworks effluent compared with no irrigation. E. globulus had the highest biomass and nutrient accumulation either irrigated with effluent or without irrigation. After 3-year growth, E. globulus stands irrigated with effluent accumulated 72 oven dry t/ha of above-ground total biomass with a total of 651 kg N, 55 kg P, 393 kg K, 251 kg Ca, 35 kg Mg and 67 kg Mn. Effluent irrigation increased the accumulation of biomass, N, P, K and Mn, but tended to reduce the leaf area index and leaf biomass, and decreased the accumulation of Ca and Mg. (author)

  8. Environmental impacts of innovative dairy farming systems aiming at improved internal nutrient cycling: a multi-scale assessment

    NARCIS (Netherlands)

    Vries, de W.; Kros, J.; Dolman, M.A.; Vellinga, Th.V.; Boer, de H.C.; Sonneveld, M.P.W.; Bouma, J.

    2015-01-01

    Several dairy farms in the Netherlands aim at reducing environmental impacts by improving the internal nutrient cycle (INC) on their farm by optimizing the use of available on-farm resources. This study evaluates the environmental performance of selected INC farms in the Northern Friesian Woodlands

  9. Nutrient limitation reduces land carbon uptake in simulations with a model of combined carbon, nitrogen and phosphorus cycling

    Directory of Open Access Journals (Sweden)

    D. S. Goll

    2012-09-01

    Full Text Available Terrestrial carbon (C cycle models applied for climate projections simulate a strong increase in net primary productivity (NPP due to elevated atmospheric CO2 concentration during the 21st century. These models usually neglect the limited availability of nitrogen (N and phosphorus (P, nutrients that commonly limit plant growth and soil carbon turnover. To investigate how the projected C sequestration is altered when stoichiometric constraints on C cycling are considered, we incorporated a P cycle into the land surface model JSBACH (Jena Scheme for Biosphere–Atmosphere Coupling in Hamburg, which already includes representations of coupled C and N cycles.

    The model reveals a distinct geographic pattern of P and N limitation. Under the SRES (Special Report on Emissions Scenarios A1B scenario, the accumulated land C uptake between 1860 and 2100 is 13% (particularly at high latitudes and 16% (particularly at low latitudes lower in simulations with N and P cycling, respectively, than in simulations without nutrient cycles. The combined effect of both nutrients reduces land C uptake by 25% compared to simulations without N or P cycling. Nutrient limitation in general may be biased by the model simplicity, but the ranking of limitations is robust against the parameterization and the inflexibility of stoichiometry. After 2100, increased temperature and high CO2 concentration cause a shift from N to P limitation at high latitudes, while nutrient limitation in the tropics declines. The increase in P limitation at high-latitudes is induced by a strong increase in NPP and the low P sorption capacity of soils, while a decline in tropical NPP due to high autotrophic respiration rates alleviates N and P limitations. The quantification of P limitation remains challenging. The poorly constrained processes of soil P sorption and biochemical mineralization are identified as the main uncertainties in the strength of P limitation

  10. Effects of changes in nutrient loading and composition on hypoxia dynamics and internal nutrient cycling of a stratified coastal lagoon

    Science.gov (United States)

    Zhu, Yafei; McCowan, Andrew; Cook, Perran L. M.

    2017-10-01

    The effects of changes in catchment nutrient loading and composition on the phytoplankton dynamics, development of hypoxia and internal nutrient dynamics in a stratified coastal lagoon system (the Gippsland Lakes) were investigated using a 3-D coupled hydrodynamic biogeochemical water quality model. The study showed that primary production was equally sensitive to changed dissolved inorganic and particulate organic nitrogen loads, highlighting the need for a better understanding of particulate organic matter bioavailability. Stratification and sediment carbon enrichment were the main drivers for the hypoxia and subsequent sediment phosphorus release in Lake King. High primary production stimulated by large nitrogen loading brought on by a winter flood contributed almost all the sediment carbon deposition (as opposed to catchment loads), which was ultimately responsible for summer bottom-water hypoxia. Interestingly, internal recycling of phosphorus was more sensitive to changed nitrogen loads than total phosphorus loads, highlighting the potential importance of nitrogen loads exerting a control over systems that become phosphorus limited (such as during summer nitrogen-fixing blooms of cyanobacteria). Therefore, the current study highlighted the need to reduce both total nitrogen and total phosphorus for water quality improvement in estuarine systems.

  11. Effects of changes in nutrient loading and composition on hypoxia dynamics and internal nutrient cycling of a stratified coastal lagoon

    Directory of Open Access Journals (Sweden)

    Y. Zhu

    2017-10-01

    Full Text Available The effects of changes in catchment nutrient loading and composition on the phytoplankton dynamics, development of hypoxia and internal nutrient dynamics in a stratified coastal lagoon system (the Gippsland Lakes were investigated using a 3-D coupled hydrodynamic biogeochemical water quality model. The study showed that primary production was equally sensitive to changed dissolved inorganic and particulate organic nitrogen loads, highlighting the need for a better understanding of particulate organic matter bioavailability. Stratification and sediment carbon enrichment were the main drivers for the hypoxia and subsequent sediment phosphorus release in Lake King. High primary production stimulated by large nitrogen loading brought on by a winter flood contributed almost all the sediment carbon deposition (as opposed to catchment loads, which was ultimately responsible for summer bottom-water hypoxia. Interestingly, internal recycling of phosphorus was more sensitive to changed nitrogen loads than total phosphorus loads, highlighting the potential importance of nitrogen loads exerting a control over systems that become phosphorus limited (such as during summer nitrogen-fixing blooms of cyanobacteria. Therefore, the current study highlighted the need to reduce both total nitrogen and total phosphorus for water quality improvement in estuarine systems.

  12. Nutrient attenuation in rivers and streams, Puget Sound Basin, Washington

    Science.gov (United States)

    Sheibley, Rich W.; Konrad, Christopher P.; Black, Robert W.

    2015-01-01

    Nutrients such as nitrogen and phosphorus are important for aquatic ecosystem health. Excessive amounts of nutrients, however, can make aquatic ecosystems harmful for biota because enhanced growth and decay cycles of aquatic algae can reduce dissolved oxygen in the water. In Puget Sound marine waters, low dissolved oxygen concentrations are observed in a number of marine nearshore areas, and nutrients have been identified as a major stressor to the local ecosystem. Delivery of nutrients from major rivers in the Puget Sound Basin to the marine environment can be large. Therefore, it is important to identify factors related to how nutrients are retained (attenuated) within streams and rivers in the Puget Sound Basin. Physical, chemical, and biological factors related to nutrient attenuation were identified through a review of related scientific literature.

  13. Wetland development, permafrost history and nutrient cycling inferred from late Holocene peat and lake sediment records in subarctic Sweden

    DEFF Research Database (Denmark)

    Kokfelt, U.; Reuss, N.; Struyf, E.

    2010-01-01

    Sweden to address the late Holocene (5,000 cal BP-present) development of the mire as well as related changes in carbon and nutrient cycling. Formation, sediment accumulation and biogeochemistry of two studied lakes are suggested to be largely controlled by the development of the mire and its permafrost......-induced changes in hydrology may further have affected the inflow of alkaline water from the catchment. Elevated contents of biogenic silica and diatom pigments in lake sediments during periods of poor fen and bog expansion further indicate that terrestrial vegetation influenced the amount of nutrients entering...

  14. Nutrient solution aeration and growing cycles affect quality and yield of fresh-cut baby leaf red lettuce

    Directory of Open Access Journals (Sweden)

    Encarnación Conesa

    2015-12-01

    Full Text Available The objective of this research was to study the effects of nutrient solution aeration [no aeration (NA, low aeration (LA or high aeration (HA] and growing cycle (autumn, winter and summer on the yield, quality, and shelf life of red lettuce as a fresh-cut product grown in a floating system. The specific leaf area, yield and root diameter were affected by the growing cycle. The percentage of dry matter and the nitrate content were affected by growing cycle and aeration, total phenolics and mesophilic microorganism by aeration and storage time, hue angle and chromacity by growing cycle and storage time, and antioxidant capacity, vitamin C, lightness and psychrophilic microorganisms were affected by all three factors. NA conditions increased the antioxidant capacity in summer and vitamin C content in winter. The lowest mesophilic and psychrophilic count was observed in autumn. The effect of aeration on most of the quality parameters measured was influenced by the growing cycle.

  15. Sampling strategies for tropical forest nutrient cycling studies: a case study in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    G. Sparovek

    1997-12-01

    Full Text Available The precise sampling of soil, biological or micro climatic attributes in tropical forests, which are characterized by a high diversity of species and complex spatial variability, is a difficult task. We found few basic studies to guide sampling procedures. The objective of this study was to define a sampling strategy and data analysis for some parameters frequently used in nutrient cycling studies, i. e., litter amount, total nutrient amounts in litter and its composition (Ca, Mg, Κ, Ν and P, and soil attributes at three depths (organic matter, Ρ content, cation exchange capacity and base saturation. A natural remnant forest in the West of São Paulo State (Brazil was selected as study area and samples were collected in July, 1989. The total amount of litter and its total nutrient amounts had a high spatial independent variance. Conversely, the variance of litter composition was lower and the spatial dependency was peculiar to each nutrient. The sampling strategy for the estimation of litter amounts and the amount of nutrient in litter should be different than the sampling strategy for nutrient composition. For the estimation of litter amounts and the amount of nutrients in litter (related to quantity a large number of randomly distributed determinations are needed. Otherwise, for the estimation of litter nutrient composition (related to quality a smaller amount of spatially located samples should be analyzed. The determination of sampling for soil attributes differed according to the depth. Overall, surface samples (0-5 cm showed high short distance spatial dependent variance, whereas, subsurface samples exhibited spatial dependency in longer distances. Short transects with sampling interval of 5-10 m are recommended for surface sampling. Subsurface samples must also be spatially located, but with transects or grids with longer distances between sampling points over the entire area. Composite soil samples would not provide a complete

  16. Metagenomic Insights Into the Microbial Community and Nutrient Cycling in the Western Subarctic Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Yingdong Li

    2018-04-01

    Full Text Available The composition and metabolic functions of prokaryotic communities in the western subarctic Pacific (WSP, where strong mixing of waters from the Sea of Okhotsk and the East Kamchatka Current result in transfer to the Oyashio Current, were investigated using a shotgun metagenome sequencing approach. Functional metabolic genes related to nutrient cycling of nitrogen, sulfur, carbohydrates, iron and amino acids were differently distributed between the surface and deep waters of the WSP. Genes related to nitrogen metabolism were mainly found in deep waters, where Thaumarchaeaota, Sphingomonadales, and Pseudomonadales were closely associated and performing important roles in ammonia oxidation, assimilatory nitrate reduction, and dissimilatory nitrate reduction processes, respectively. In addition, orders affiliated to Spingobacteria and Alphaproteobacteria were crucial for sulfate reduction and abundant at 3000 m, whereas orders affiliated to Gammaproteobacteria, which harbored the most sulfate reduction genes, were abundant at 1000 m. Additionally, when compared with the East Kamchatka Current, the prokaryotes in the Oyashio Current were likely to consume more energy for synthesizing cellular components. Also, genes encoding iron transport and siderophore biosynthesis proteins were in low abundance, indicating that the iron was not a limiting factor in the Oyashio current. In contrast, in the East Kamchatka Current, prokaryotes were more likely to directly utilize the amino acids and absorb iron from the environment. Overall, our data indicated that the transformation from the East Kamchatka Current to the Oyashio Current reshapes not only the composition of microbial community, but also the function of the metabolic processes. These results extended our knowledge of the microbial composition and potential metabolism in the WSP.

  17. Metagenomic Insights Into the Microbial Community and Nutrient Cycling in the Western Subarctic Pacific Ocean.

    Science.gov (United States)

    Li, Yingdong; Jing, Hongmei; Xia, Xiaomin; Cheung, Shunyan; Suzuki, Koji; Liu, Hongbin

    2018-01-01

    The composition and metabolic functions of prokaryotic communities in the western subarctic Pacific (WSP), where strong mixing of waters from the Sea of Okhotsk and the East Kamchatka Current result in transfer to the Oyashio Current, were investigated using a shotgun metagenome sequencing approach. Functional metabolic genes related to nutrient cycling of nitrogen, sulfur, carbohydrates, iron and amino acids were differently distributed between the surface and deep waters of the WSP. Genes related to nitrogen metabolism were mainly found in deep waters, where Thaumarchaeaota, Sphingomonadales , and Pseudomonadales were closely associated and performing important roles in ammonia oxidation, assimilatory nitrate reduction, and dissimilatory nitrate reduction processes, respectively. In addition, orders affiliated to Spingobacteria and Alphaproteobacteria were crucial for sulfate reduction and abundant at 3000 m, whereas orders affiliated to Gammaproteobacteria , which harbored the most sulfate reduction genes, were abundant at 1000 m. Additionally, when compared with the East Kamchatka Current, the prokaryotes in the Oyashio Current were likely to consume more energy for synthesizing cellular components. Also, genes encoding iron transport and siderophore biosynthesis proteins were in low abundance, indicating that the iron was not a limiting factor in the Oyashio current. In contrast, in the East Kamchatka Current, prokaryotes were more likely to directly utilize the amino acids and absorb iron from the environment. Overall, our data indicated that the transformation from the East Kamchatka Current to the Oyashio Current reshapes not only the composition of microbial community, but also the function of the metabolic processes. These results extended our knowledge of the microbial composition and potential metabolism in the WSP.

  18. Multiple constraint modeling of nutrient cycling stoichiometry following forest clearing and pasture abandonment in the Eastern Amazon

    Science.gov (United States)

    Davidson, Eric; Nifong, Rachel

    2017-04-01

    While deforestation has declined since its peak, land-use change continues to modify Amazonian landscapes. The responses and feedbacks of biogeochemical cycles to these changes play an important role in determining possible future trajectories of ecosystem function and for land stewardship through effects on rates of secondary forest regrowth, soil emissions of greenhouse gases, inputs of nutrients to groundwater and streamwater, and nutrient management in agroecosystems. Here we present a new synthetic analyses of data from the NASA-supported LBA-ECO project and others datasets on nutrient cycling in cattle pastures, secondary forests, and mature forests at Paragominas, Pará, Brazil. We have developed a stoichiometric model relating C-N-P interactions during original forest clearing, extensive and intensive pasture management, and secondary forest regrowth, constrained by multiple observations of ecosystem stocks and fluxes in each land use. While P is conservatively cycled in all land uses, we demonstrate that pyrolyzation of N during pasture formation and during additional burns for pasture management depletes available-N pools, consistent with observations of lower rates of N leaching and trace gas emission and consistent with secondary forest growth responses to experimental N amendments. The soils store large stocks of N and P, and our parameterization of available forms of these nutrients for steady-state dynamics in the mature forest yield reasonable estimates of net N and P mineralization available for grasses and secondary forest species at rates consistent with observed biomass accumulation and productivity in these modified ecosystems. Because grasses and forests have much different demands for N relative to P, the land use has important biogeochemical impacts. The model demonstrates the need for periodic P inputs for sustainable pasture management and for a period of significant biological N fixation for early-to-mid-successional secondary forest

  19. CICLAJE Y PÉRDIDA DE NUTRIENTES DEL SUELO EN BOSQUES ALTOANDINOS DE ANTIOQUIA, COLOMBIA NUTRIENT CYCLING AND NUTRIENT LOSSES IN ANDEAN MONTANE FORESTS FROM ANTIOQUIA, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Adriana Londoño Álvarez

    2007-06-01

    Full Text Available El agua gravitacional y su composición química fueron medidos en bosques montanos de Quercus humboldtii y reforestados (Pinus patula y Cupressus lusitanica de la región de Piedras Blancas, Antioquia (Colombia, por un período de tiempo de dos años. Se utilizaron lisímetros sin tensión con el fin de estimar el agua gravitacional y los flujos de nutrientes a diferentes profundidades en el perfil del suelo. El mayor valor anual de agua gravitacional en el nivel más profundo (50- 80 cm, fue hallado en la cobertura de ciprés ( 492,7 mm, seguido por pino pátula ( 14,2 mm y roble ( 2,0 mm. De manera similar ocurrió con la pérdida de nutrientes, mostrando el mismo patrón hallado para el agua gravitacional. Así, para roble, pátula y ciprés, en su orden, se presentaron los siguientes valores de pérdida: Ca: 0,004, 0,084 y 2,270 kg ha-1 año-1; P: 0,008, 0,052 y 1,234 kg ha-1 año-1; Mg: 0,004, 0,022 y 0,667 kg ha-1 año-1. De K se registraron 0,08 y 7,092 kg ha-1 año-1 para roble y ciprés respectivamente. Estos flujos siguieron el siguiente orden según cobertura, roble: K>P>Ca>Mg, pátula: Ca>Fe>P>Mg>Zn>Mn, y ciprés: K>Mn>Ca>P>Fe>Zn>Mg.Gravitational flow and its chemical composition were measured in montane oak forests (Quercus humboldtii, in pine (Pinus patula and cypress (Cupressus lusitanica plantations in Piedras Blancas, Antioquia ( Colombia , over two years. Zero tension lysimeters were used at different depth soil levels. The highest gravitational flow value at highest depth (50- 80 cm was obtained in cypress plot ( 492,7 mm, followed by pine ( 14,2 mm and oak forest ( 2,0 mm. A similar behavior was encountered for nutrient losses, following the same pattern as gravitational flow. Thus, for oak, pine and cypress, nutrient losses were respectively: Ca: 0,004, 0,084 and 2,270 kg ha-1 y-1; P: 0,008, 0,052 and 1,234 kg ha-1 y -1; Mg: 0,004, 0,022 and 0,667 kg ha-1 y-1. K losses were 0,08 and 7,092 kg ha-1 y-1 for oak forest and

  20. Effects of freeze-thaw cycles on microarthropods and nutrient availability in a sub-arctic soil

    DEFF Research Database (Denmark)

    Sjursen, Heidi; Michelsen, Anders; Holmstrup, Martin

    2005-01-01

    and their environment, intact plant-soil samples from the sub-Arctic were subjected to a series of such events. Springtail and mite species composition and abundance were monitored at intervals throughout the experiment. Furthermore, nutrient content and mobilisation in the soil and soil microbial biomass and nutrient......It is predicted that Arctic regions may experience an increase in mean temperature in the future. This will affect the frequency of severe climatic events such as summer droughts and freeze-thaw cycles. In order to understand the impact of recurring freezing and thawing on soil organisms...... content were examined. There was no conclusive evidence that recurring freeze-thaw events had a negative effect on the investigated soil faunal groups, and the treatment even seemed to stimulate the abundance of Acaridida. Respiration of soil subjected to 16 freeze-thaw cycles was low when kept at -2 °C...

  1. Effects of Fallow Genealogical Cycles on the Build-up of Nutrients in ...

    African Journals Online (AJOL)

    Dr Osondu

    2012-01-04

    Jan 4, 2012 ... generations. As usual, nutrients in the fallow generations were confined to the topsoil. The increase in soil nutrients was attributed to the increased in tree size, vegetation cover and ... years, is termed 1st generation fallow, one that is ...... ns: Difference between means is not significant at 5% alpha level.

  2. The subtropical nutrient spiral

    Science.gov (United States)

    Jenkins, William J.; Doney, Scott C.

    2003-12-01

    We present an extended series of observations and more comprehensive analysis of a tracer-based measure of new production in the Sargasso Sea near Bermuda using the 3He flux gauge technique. The estimated annually averaged nitrate flux of 0.84 ± 0.26 mol m-2 yr-1 constitutes only that nitrate physically transported to the euphotic zone, not nitrogen from biological sources (e.g., nitrogen fixation or zooplankton migration). We show that the flux estimate is quantitatively consistent with other observations, including decade timescale evolution of the 3H + 3He inventory in the main thermocline and export production estimates. However, we argue that the flux cannot be supplied in the long term by local diapycnal or isopycnal processes. These considerations lead us to propose a three-dimensional pathway whereby nutrients remineralized within the main thermocline are returned to the seasonally accessible layers within the subtropical gyre. We describe this mechanism, which we call "the nutrient spiral," as a sequence of steps where (1) nutrient-rich thermocline waters are entrained into the Gulf Stream, (2) enhanced diapycnal mixing moves nutrients upward onto lighter densities, (3) detrainment and enhanced isopycnal mixing injects these waters into the seasonally accessible layer of the gyre recirculation region, and (4) the nutrients become available to biota via eddy heaving and wintertime convection. The spiral is closed when nutrients are utilized, exported, and then remineralized within the thermocline. We present evidence regarding the characteristics of the spiral and discuss some implications of its operation within the biogeochemical cycle of the subtropical ocean.

  3. River Metabolism and Nutrient Cycling at the Point Scale: Insights from In Situ Sensors in Benthic Chambers

    Science.gov (United States)

    Cohen, M. J.; Reijo, C. J.; Hensley, R. T.

    2017-12-01

    Riverine processing of nutrients and carbon is a local process, subject to heterogeneity in sediment, biotic, insolation, and flow velocity drivers. Measurements at the reach scale aggregate across riverscapes, limiting their utility for enumerating these drivers, and thus for scaling to river networks. Using a combination of in situ sensors that sample water chemistry at high temporal resolution and open benthic chambers that isolate the biogeochemical impacts of a small footprint of benthic surface area, we explored controls on metabolism and nutrient cycling. We specifically sought to answer two questions. First, what are the controls on primary production, with a particular emphasis on the relative roles of light vs. nutrient limitation? Second, what are the pathways of nutrient retention, and do the reaction kinetics of these different pathways differ? We demonstrate the considerable utility of these benthic chambers, reasoning that they provide experimental units for river processes that are not attainable at the reach or network scale. Specifically, in addition to their ability to sample the heterogeneity of the river bed as well as observe nutrient depletion to create concentrations well below ambient levels, they enable manipulative experiments (e.g., nutrient enrichment, light reduction, grazer adjustments) while retaining key elements of the natural system. Across several of Florida's spring-fed river sites, our results strongly support the primacy of light limitation of primary production, with very little evidence of any incremental effects of nutrient enrichment. Nutrient depletion assays further support the dominance of two N retention mechanisms (denitrification and assimilation), the kinetics of which differ markedly, with denitrification exhibiting nearly first-order reactions, and assimilation following zero-order or Michaelis-Menten kinetics over the range of observed concentrations. This latter result helps explain the absence of strong

  4. Presence and patterns of alkaline phosphatase activity and phosphorus cycling in natural riparian zones under changing nutrient conditions

    Directory of Open Access Journals (Sweden)

    Peifang Wang

    2014-08-01

    Full Text Available Phosphorus (P is an important limiting nutrient in aquatic ecosystems and knowledge of P cycling is fundamental for reducing harmful algae blooms and other negative effects in water. Despite their importance, the characteristics of P cycling under changing nutrient conditions in shallow lakes were poorly investigated. In this study, in situ incubation experiments were conducted in a natural riparian zone in the main diversion channel used for water transfer into Lake Taihu (Wangyu River. Variations in microbial biomass, dissolved P fractions (organic and inorganic, and alkaline phosphatase activity (bulk APA and specific APA were determined after incubation with and without the addition of P and nitrogen (N (4 total water treatments: +P, +N, +NP, and control. Experiments were conducted during two seasons (late spring and early fall to account for natural differences in nutrient levels that may occur in situ. Our results demonstrated that low levels of DRP may not necessarily indicate P limitation. Phytoplankton exhibited “serial N limitation with P stress” in May, such that chlorophyll a (Chl a increased significantly with N addition, while the limiting nutrient shifted to P in October and phytoplankton biomass increased with P addition. Phytoplankton contributed greatly to APA production and was significantly influenced by P bioavailability, yet high levels of bulk APA were also not necessarily indicative of P limitation. In contrast to phytoplankton, bacteria were less P stressed. As a consequence of enhanced utilization of dissolved reactive P (DRP and dissolved organic P (DOP, +N treatment elevated APA significantly. By contrast, APA could be repressed to low values and phytoplankton converted a large portion of DRP to DOP with P addition. But this was not consistent with bacteria APA (bact-APA in the absence or presence of abundant phytoplankton biomass. The correlation between bulk APA and DRP was good at separate sites and discrepant

  5. Design and construction of a vertical hydroponic system with semi-continuous and continuous nutrient cycling

    Science.gov (United States)

    Siswanto, Dian; Widoretno, Wahyu

    2017-11-01

    Problems due to the increase in agricultural land use change can be solved by hydroponic system applications. Many hydroponic studies have been conducted in several countries while their applications in Indonesia requires modification and adjustment. This research was conducted to design and construct a hydroponic system with semi-continuous and continuous nutrition systems. The hydroponic system which was used adapts the ebb and flow system, and the nutrient film technique (NFT). This hydroponic system was made from polyvinyl chloride (PVC) pipes with a length of 197 cm, a diameter of 16 cm, and a slope of 4°. It was constructed from four PVC pipes. In semi-continuous irrigation treatment, nutrients flow four to six times for each of ten minutes depending on plant development and the estimated evapotranspiration occurring, while in a continuous nutrient system the nutrients are streamed for twenty-four hours without stopping at a maximum flow rate of 13.7 L per second.

  6. Wetland development, permafrost history and nutrient cycling inferred from late Holocene peat and lake sediment records in subarctic Sweden

    DEFF Research Database (Denmark)

    Kokfelt, U.; Reuss, N.; Struyf, E.

    2010-01-01

    -induced changes in hydrology may further have affected the inflow of alkaline water from the catchment. Elevated contents of biogenic silica and diatom pigments in lake sediments during periods of poor fen and bog expansion further indicate that terrestrial vegetation influenced the amount of nutrients entering...... Sweden to address the late Holocene (5,000 cal BP-present) development of the mire as well as related changes in carbon and nutrient cycling. Formation, sediment accumulation and biogeochemistry of two studied lakes are suggested to be largely controlled by the development of the mire and its permafrost...... to re-deposition of peat into one of the lakes after ca. 2,100 cal BP, and stimulated primary productivity in the other lake at ca. 1,900-1,800 cal BP. Carbonate precipitation appears to have been suppressed when acidic poor fen and bog (palsa) communities dominated the catchment mire, and permafrost...

  7. Nutrient cycling for biomass: Interactive proteomic/transcriptomic networks for global carbon management processes within poplar-mycorrhizal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Cseke, Leland [Univ. of Alabama, Huntsville, AL (United States)

    2016-08-30

    free living conditions. Together, the assembled team of experts completed all of the planned milestones set forth in this project. In addition to the planned approaches, several lines of exciting new research have also evolved during the course of this project that involved FTIR Imaging using the National Synchrotron Light Source at BNL. A summary of the approaches used in this project and key highlights are as follows: Having the right combination of microbes associated with plants is largely responsible for the plant’s ability to mine nutrients from the soil and to develop a strong “immune system”. Our current chemically focused and intensive culture tends to forget that plants obtain nutrients in two ways: (1) via water soluble chemical nutrients and (2) via the activity of acquired microbial symbionts. In healthy natural ecosystems, chemical nutrients are always in low abundance because the organisms within that system have already locked such nutrients away within the biological system itself. Thus, in nature it is the biological sources of nutrients and the microbes that have the capacity to mine those nutrients for their plant hosts that actually control the terrestrial nutrient cycles on this planet. Thus, a new push in the future may very well be to use our skills at elucidating complex patterns to strategically guide soil microbe communities to do what we want, essentially allowing nature to do the work of figuring out what is most efficient and effective for human needs. However, the findings of this project and other work in our lab lead to the hypothesis that the specific soil community composition is less important than the emergent properties of those communities. So, additional research into what soil communities are effective and how they are established will be key in developing human understanding of how to manipulate biological systems to meet human needs without causing undue damage to our environment.

  8. Closing the Global Energy and Nutrient Cycles through Application of Biogas Residue to Agricultural Land – Potential Benefits and Drawback

    Directory of Open Access Journals (Sweden)

    Veronica Arthurson

    2009-04-01

    Full Text Available Anaerobic digestion is an optimal way to treat organic waste matter, resulting in biogas and residue. Utilization of the residue as a crop fertilizer should enhance crop yield and soil fertility, promoting closure of the global energy and nutrient cycles. Consequently, the requirement for production of inorganic fertilizers will decrease, in turn saving significant amounts of energy, reducing greenhouse gas emissions to the atmosphere, and indirectly leading to global economic benefits. However, application of this residue to agricultural land requires careful monitoring to detect amendments in soil quality at the early stages.

  9. Ecosystem services driven by the diversity of soil biota - understanding and management in agriculture - The Biodiversa SoilMan-Project

    Science.gov (United States)

    Potthoff, Martin; Pérès, Guénola; Taylor, Astrid; Schrader, Stefan; Landa, Blanca; Nicolai, Annegret; Sandor, Mignon; Öptik, Maarja; Gema, Guzmán; Bergmann, Holger; Cluzeau, Daniel; Banse, Martin; Bengtsson, Jan; Guernion, Muriel; Zaller, Johann; Roslin, Tomas; Scheu, Stefan; Gómez Calero, José Alfonso

    2017-04-01

    Soil biota diversity is ensuring primary production in terrestrial ecosystems and agricultural productivity. Water and nutrient cycling, soil formation and aggregation, decomposition and carbon sequestration as well as control of pest organisms are important functions in soil that are driven by biota and biota interactions. In agricultural systems these functions support and regulate ecosystem services directed to agricultural production and agricultural sustainability. A main goal of future cropping systems will be to maintain or raise agricultural productivity while keeping production sustainable in spite of increasing food demands and ongoing soil degradation caused by inappropriate soil management practices. Farm based tools that farmers use to engineer soils for plant production depend as soil management factors on decisions by farmers, which are triggered by regional traditions, knowledge and also by agriculture policies as a governance impact. However, biological impacts on soil fertility and soil health are often neglected or overseen when planning and shaping soil management in annual cropping systems or perennial systems like vineyards. In order to get progress in conservation farming and in agricultural sustainability not only knowledge creation is in need, but also a clash of perspectives has to be overcome within the societies (generals public, farmers associations, NGOs) The talk will present the conception of the recently startet SoilMan-project and summaries selected results from current and recent European research projects.

  10. Life cycle comparison of centralized wastewater treatment and urine source separation with struvite precipitation: Focus on urine nutrient management.

    Science.gov (United States)

    Ishii, Stephanie K L; Boyer, Treavor H

    2015-08-01

    Alternative approaches to wastewater management including urine source separation have the potential to simultaneously improve multiple aspects of wastewater treatment, including reduced use of potable water for waste conveyance and improved contaminant removal, especially nutrients. In order to pursue such radical changes, system-level evaluations of urine source separation in community contexts are required. The focus of this life cycle assessment (LCA) is managing nutrients from urine produced in a residential setting with urine source separation and struvite precipitation, as compared with a centralized wastewater treatment approach. The life cycle impacts evaluated in this study pertain to construction of the urine source separation system and operation of drinking water treatment, decentralized urine treatment, and centralized wastewater treatment. System boundaries include fertilizer offsets resulting from the production of urine based struvite fertilizer. As calculated by the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI), urine source separation with MgO addition for subsequent struvite precipitation with high P recovery (Scenario B) has the smallest environmental cost relative to existing centralized wastewater treatment (Scenario A) and urine source separation with MgO and Na3PO4 addition for subsequent struvite precipitation with concurrent high P and N recovery (Scenario C). Preliminary economic evaluations show that the three urine management scenarios are relatively equal on a monetary basis (<13% difference). The impacts of each urine management scenario are most sensitive to the assumed urine composition, the selected urine storage time, and the assumed electricity required to treat influent urine and toilet water used to convey urine at the centralized wastewater treatment plant. The importance of full nutrient recovery from urine in combination with the substantial chemical inputs required for N recovery

  11. Coupling hydrological and impact assessment models to explore nutrient cycling in freshwater systems

    Science.gov (United States)

    Bouwman, Lex; van Beek, Rens; Beusen, Arthur; Mogollón, José; Middelburg, Jack

    2016-04-01

    The IMAGE-Global Nutrient Model (GNM) is a new globally distributed, spatially explicit model in which the hydrology model PCR-GLOBWB is coupled to the integrated assessment model IMAGE to simulate nitrogen (N) and phosphorus (P) delivery, and then with a spiraling ecological approach to simulating instream biogeochemistry. Routing the water with dissolved and suspended N and P from upstream grid cells occurs simultaneous with N and P delivery to water bodies within grid cells from diffuse and point sources (wastewater). IMAGE-GNM describes the following diffuse sources associated with the water flow: surface runoff, shallow and deep groundwater, riparian zones. Depending on the landscape features, all these flows may be present within one grid cell. Furthermore, diffuse N and P inputs occur through allochtonous organic matter inputs via litterfall in (temporarily) inundated river floodplains, and atmospheric deposition. In the spiraling concept, the residence time of the water and nutrient uptake velocity determine N and P retention in water bodies. Validation of model results with observations yields acceptable agreement given the global scale of the uncalibrated model. Sensitivity analysis shows shifts in the importance of the different sources, with decreasing importance of natural sources and increasing influence of wastewater and agriculture. IMAGE-GNM can be employed to study the interaction between society and the environment over prolonged time periods. Here we show results for the full 20th century.

  12. Optimal Management of Water, Nutrient and Carbon Cycles of Green Urban Spaces

    Science.gov (United States)

    Revelli, R.; Pelak, N. F., III; Porporato, A. M.

    2016-12-01

    The urban ecosystem is a complex, metastable system with highly coupled flows of mass, energy, people and capital. Their sustainability is in part linked to the existence of green spaces which provide important ecosystem services, whose sustainable management requires quantification of their benefits in terms of impacts on water, carbon and energy fluxes. An exploration of problems of optimal management of such green urban spaces and the related biogeochemical fluxes is presented, extending probabilistic ecohydrological models of the soil-plant system to the urban context, where biophysical and ecological conditions tend to be radically different from the surrounding rural and natural environment (e.g. heat islands, air and water pollution, low quality soils, etc…). The coupled soil moisture, nutrient and plant dynamics are modeled to compute water requirements, carbon footprint, nutrient demand and losses, and related fluxes under different design, management and climate scenarios. The goal is to provide operative rules for a sustainable water use through focused irrigation and fertilization strategies, optimal choice of plants, soil and cultivation conditions, accounting for the typical hydroclimatic variability that occur in the urban environment. This work is part of a project that has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 701914. The work is also cofounded by USDA Agricultural Research Service cooperative agreement 58-6408-3-027; National Science Foundation (NSF) grants: EAR-1331846, EAR-1316258, and the DGE-1068871 and FESD EAR-1338694.

  13. Combined use of stable isotopes and hydrologic modeling to better understand nutrient sources and cycling in highly altered systems (Invited)

    Science.gov (United States)

    Young, M. B.; Kendall, C.; Guerin, M.; Stringfellow, W. T.; Silva, S. R.; Harter, T.; Parker, A.

    2013-12-01

    The Sacramento and San Joaquin Rivers provide the majority of freshwater for the San Francisco Bay Delta. Both rivers are important sources of drinking and irrigation water for California, and play critical roles in the health of California fisheries. Understanding the factors controlling water quality and primary productivity in these rivers and the Delta is essential for making sound economic and environmental water management decisions. However, these highly altered surface water systems present many challenges for water quality monitoring studies due to factors such as multiple potential nutrient and contaminant inputs, dynamic source water inputs, and changing flow regimes controlled by both natural and engineered conditions. The watersheds for both rivers contain areas of intensive agriculture along with many other land uses, and the Sacramento River receives significant amounts of treated wastewater from the large population around the City of Sacramento. We have used a multi-isotope approach combined with mass balance and hydrodynamic modeling in order to better understand the dominant nutrient sources for each of these rivers, and to track nutrient sources and cycling within the complex Delta region around the confluence of the rivers. High nitrate concentrations within the San Joaquin River fuel summer algal blooms, contributing to low dissolved oxygen conditions. High δ15N-NO3 values combined with the high nitrate concentrations suggest that animal manure is a significant source of nitrate to the San Joaquin River. In contrast, the Sacramento River has lower nitrate concentrations but elevated ammonium concentrations from wastewater discharge. Downstream nitrification of the ammonium can be clearly traced using δ15N-NH4. Flow conditions for these rivers and the Delta have strong seasonal and inter-annual variations, resulting in significant changes in nutrient delivery and cycling. Isotopic measurements and estimates of source water contributions

  14. Groundwater Availability Alters Soil-plant Nutrient Cycling in a Stand of Invasive, N-fixing Phreatophytes

    Science.gov (United States)

    Dudley, B. D.; Miyazawa, Y.; Hughes, F.; Ostertag, R.; Kettwich, S. K.; MacKenzie, R.; Dulaiova, H.; Waters, C. A.; Bishop, J.; Giambelluca, T. W.

    2013-12-01

    N-fixing phreatophytic trees are common in arid and semi-arid regions worldwide, and can play significant roles in modifying hydrology and soil-plant nutrient cycling where they are present. In light of reductions in groundwater levels in many arid regions we estimated annual transpiration rates at a stand level, and alterations to C, N and P accretion in soils as a function of groundwater depth in a ca.120 year old stand of Prosopis pallida along an elevation gradient in coastal leeward Hawaii. We measured sapflow and stand level sapwood area to quantify transpiration, and calculated groundwater transpiration rates using P. pallida stem water δ18O values. By measuring soil resistivity, we were able to compare the volume of groundwater transpired by these trees to groundwater depth across the stand. We examined nutrient deposition and accretion in soils in lowland areas of the stand with accessible shallow groundwater, compared to upland areas with no groundwater access, as indicated by stem water δ18O values. Resistivity results suggested that groundwater was at a height close to sea level throughout the stand. Transpiration was around 1900 m3 ha-1 year-1 in the areas of the stand closest to the sea (where groundwater was at around 1-4 m below ground level) and decreased to around a tenth of that volume where groundwater was not accessible. Litterfall rates over the course of the year studied were 17 times greater at lowland sites, but this litterfall contributed ca. 24 times the N, and 35 times the P of upland sites. Thus, groundwater access contributed to the total mass of nitrogen and phosphorus deposited in the form of litter through higher litter quantity and quality. Total N content of soils was 4.7 times greater and inorganic N pools were eight times higher at lowland plots. These results suggest that groundwater depth can have strong effects on soil-plant nutrient cycling, so that reductions in the availability of shallow groundwater are likely to impact

  15. How do persistent organic pollutants be coupled with biogeochemical cycles of carbon and nutrients in terrestrial ecosystems under global climate change?

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Ying [Chinese Academy of Sciences, Nanjing (China). Key Lab. of Soil Environment and Pollution Remediation; Griffith Univ., Nathan, QLD (Australia). Environmetnal Futures Centre and School of Biomolecular and Physical Sciences; Xu, Zhihong; Reverchon, Frederique [Griffith Univ., Nathan, QLD (Australia). Environmetnal Futures Centre and School of Biomolecular and Physical Sciences; Luo, Yongming [Chinese Academy of Sciences, Nanjing (China). Key Lab. of Soil Environment and Pollution Remediation

    2012-03-15

    Global climate change (GCC), especially global warming, has affected the material cycling (e.g., carbon, nutrients, and organic chemicals) and the energy flows of terrestrial ecosystems. Persistent organic pollutants (POPs) were regarded as anthropogenic organic carbon (OC) source, and be coupled with the natural carbon (C) and nutrient biogeochemical cycling in ecosystems. The objective of this work was to review the current literature and explore potential coupling processes and mechanisms between POPs and biogeochemical cycles of C and nutrients in terrestrial ecosystems induced by global warming. Global warming has caused many physical, chemical, and biological changes in terrestrial ecosystems. POPs environmental fate in these ecosystems is controlled mainly by temperature and biogeochemical processes. Global warming may accelerate the re-emissions and redistribution of POPs among environmental compartments via soil-air exchange. Soil-air exchange is a key process controlling the fate and transportation of POPs and terrestrial ecosystem C at regional and global scales. Soil respiration is one of the largest terrestrial C flux induced by microbe and plant metabolism, which can affect POPs biotransformation in terrestrial ecosystems. Carbon flow through food web structure also may have important consequences for the biomagnification of POPs in the ecosystems and further lead to biodiversity loss induced by climate change and POPs pollution stress. Moreover, the integrated techniques and biological adaptation strategy help to fully explore the coupling mechanisms, functioning and trends of POPs and C and nutrient biogeochemical cycling processes in terrestrial ecosystems. There is increasing evidence that the environmental fate of POPs has been linked with biogeochemical cycles of C and nutrients in terrestrial ecosystems under GCC. However, the relationships between POPs and the biogeochemical cycles of C and nutrients are still not well understood. Further

  16. Computerizing marine biota: a rational approach

    Digital Repository Service at National Institute of Oceanography (India)

    Chavan, V.S.; Chandramohan, D.; Parulekar, A.H.

    Data on marine biota while being extensive are also patchy and scattered; thus making retrieval and dissemination of information time consuming. This emphasise the need for computerizing information on marine biota with the objective to collate...

  17. Biota-Sediment Accumulation Factor Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Biota-Sediment Accumulation Factor contains approximately 20,000 biota-sediment accumulation factors (BSAFs) from 20 locations (mostly Superfund sites) for...

  18. Biological impacts of alcohol fuel emission on selected pollinator, predatory and nutrient-cycling insects and arachnids

    Energy Technology Data Exchange (ETDEWEB)

    D' Eliscu, P.N.

    1981-01-01

    Physiological and behavioral effects of methanol, ethanol, indolene, and formaldehyde emissions on selected arthropods are related to different relative organismic activities, metabolic rates, and respiratory demands. Various species of important pollinators, predators, and nutrient-cycling insects and arachnids respond differently to tailpipe and elevated levels of emissions. A gradient of responses is related to metabolism and trophic niche. Orders tested included various Hymenoptera, Diptera, Lepidoptera, Odonata, Orthoptera, Coleoptera, Collembola, Thysanura, Araneae, Acarina, and Opiliones. Responses included narcosis, spatial disorientation, cardiac arrhythmia, flight muscle and walking leg dysfunction, decreased feeding efficiency and prey capture success ratios, and increased positive thigmotaxis. Tolerance appears to be inversely related to oxygen demand of the arthropods tested, with active fliers most susceptible, weak fliers midscale, and non-fliers most tolerant. Electronic monitoring of heart, brain, and muscle characteristics suggests neuronal and neurosynaps disruptions from alcohols and formaldehyde, and neuromuscular effects from indolene in most arthropods tested.

  19. The role of the Everglades Mangrove Ecotone Region (EMER) in regulating nutrient cycling and wetland productivity in South Florida

    Science.gov (United States)

    Rivera-Monroy, Victor H.; Twilley, Robert R.; Davis, Stephen E.; Childers, Daniel L.; Simard, Marc; Chambers, Randolph; Jaffe, Rudolf; Boyer, Joseph N.; Rudnick, David T.; Zhang, Keqi; Castañeda-Moya, Edward; Ewe, Sharon M.L.; Price, Rene M.; Coronado-Molina, Carlos; Ross, Michael; Smith, Thomas J.; Michot, Beatrice; Meselhe, Ehab; Nuttle, William; Troxler, Tiffany G.; Noe, Gregory B.

    2011-01-01

    The authors summarize the main findings of the Florida Coastal Everglades Long-Term Ecological Research (FCE-LTER) program in the EMER, within the context of the Comprehensive Everglades Restoration Plan (CERP), to understand how regional processes, mediated by water flow, control population and ecosystem dynamics across the EMER landscape. Tree canopies with maximum height -1) in the calcareous marl substrate and long hydroperiod. Phosphorus limits the EMER and its freshwater watersheds due to the lack of terrigenous sediment input and the phosphorus-limited nature of the freshwater Everglades. Reduced freshwater delivery over the past 50 years, combined with Everglades compartmentalization and a 10 cm rise in coastal sea level, has led to the landward transgression (~1.5 km in 54 years) of the mangrove ecotone. Seasonal variation in freshwater input strongly controls the temporal variation of nitrogen and P exports (99%) from the Everglades to Florida Bay. Rapid changes in nutrient availability and vegetation distribution during the last 50 years show that future ecosystem restoration actions and land use decisions can exert a major influence, similar to sea level rise over the short term, on nutrient cycling and wetland productivity in the EMER.

  20. Silicon isotope fractionation between rice plants and nutrient solution and its significance to the study of the silicon cycle

    Science.gov (United States)

    Ding, T. P.; Tian, S. H.; Sun, L.; Wu, L. H.; Zhou, J. X.; Chen, Z. Y.

    2008-12-01

    solutions. The calculated silicon isotope fractionation factor between the silicon instantaneously absorbed by rice roots and the silicon in nutrient solution vary from 0.9983 at start to 0.9995 at harvest, similar to those reported for bamboo, banana and diatoms in direction and extent. In the maturity stage, the δ30Si value of rice organs decreased from -1.33‰ in roots to -1.98‰ in stem, and then increased through -0.16‰ in leaves and 1.24‰ in husks, to 2.21‰ in grains. This trend is similar to those observed in the field grown rice and bamboo. These quantitative data provide us a solid base for understanding the mechanisms of silicon absorption, transportation and precipitation in rice plants and the role of rice growth in the continental Si cycle.

  1. Nutrient- and Climate-Induced Shifts in the Phenology of Linked Biogeochemical Cycles in a Temperate Estuary

    Directory of Open Access Journals (Sweden)

    Jeremy M. Testa

    2018-04-01

    Full Text Available The response of estuarine ecosystems to long-term changes in external forcing is strongly mediated by interactions between the biogeochemical cycling of carbon, oxygen, and inorganic nutrients. Although long-term changes in estuaries are often assessed at the annual scale, phytoplankton biomass, dissolved oxygen concentrations, and biogeochemical rate processes have strong seasonal cycles at temperate latitudes. Thus, changes in the seasonal timing, or phenology, of these key processes can reveal important features of long-term change and help clarify the nature of coupling between carbon, oxygen, and nutrient cycles. Changes in the phenology of estuarine processes may be difficult to assess, however, because many organisms are mobile and migratory, key primary and secondary producers have relatively rapid physiological turnover rates, sampling in time and space is often limited, and physical processes may dominate variability. To overcome these challenges, we have analyzed a 32-year record (1985–2016 of relatively frequent and consistent measurements of chlorophyll-a, dissolved oxygen, nitrogen, and physical drivers to understand long-term change in Chesapeake Bay. Using a suite of metrics that directly test for altered phenology, we quantified changes in the seasonal timing of key biogeochemical events, which allowed us to illustrate spatially- and seasonally-dependent shifts in the magnitude of linked biogeochemical parameters. Specifically, we found that a modest reduction in nitrate input was linked to a suppression of spring phytoplankton biomass in seaward Bay regions. This was, in turn, associated with an earlier breakup in hypoxia and decline in late-summer NH4+ accumulation in seaward waters. In contrast, we observed an increase in winter phytoplankton biomass in landward regions, which was associated with elevated early summer hypoxic volumes and NH4+ accumulation. Seasonal shifts in oxygen depletion and NH4+ accumulation are

  2. Iron-dependent nitrogen cycling in a ferruginous lake and the nutrient status of Proterozoic oceans

    DEFF Research Database (Denmark)

    Michiels, Céline C.; Darchambeau, Francois; Roland, Fleur A. E.

    2017-01-01

    Nitrogen limitation during the Proterozoic has been inferred from the great expanse of ocean anoxia under low-O2 atmospheres, which could have romoted NO3-reduction to N2 and fixed N loss from the ocean. The deep oceans were Fe rich (ferruginous) during much of this time, yet the dynamics of N...... cycling under such conditions remain entirely conceptual, as analogue environments are rare today. Here we use incubation experiments to show that a modern ferruginous basin, Kabuno Bay in East Africa, supports high rates of NO3- reduction. Although 60% of this NO3- is reduced to N2 through canonical...

  3. Cancer cell metabolism and mitochondria: Nutrient plasticity for TCA cycle fueling.

    Science.gov (United States)

    Corbet, Cyril; Feron, Olivier

    2017-08-01

    Warburg's hypothesis that cancer cells take up a lot of glucose in the presence of ambient oxygen but convert pyruvate into lactate due to impaired mitochondrial function led to the misconception that cancer cells rely on glycolysis as their major source of energy. Most recent 13 C-based metabolomic studies, including in cancer patients, indicate that cancer cells may also fully oxidize glucose. In addition to glucose-derived pyruvate, lactate, fatty acids and amino acids supply substrates to the TCA cycle to sustain mitochondrial metabolism. Here, we discuss how the metabolic flexibility afforded by these multiple mitochondrial inputs allows cancer cells to adapt according to the availability of the different fuels and the microenvironmental conditions such as hypoxia and acidosis. In particular, we focused on the role of the TCA cycle in interconnecting numerous metabolic routes in order to highlight metabolic vulnerabilities that represent attractive targets for a new generation of anticancer drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Evaluating the effect of nutrient redistribution by animals on the phosphorus cycle of lowland Amazonia

    Directory of Open Access Journals (Sweden)

    C. Buendía

    2018-01-01

    Full Text Available Phosphorus (P availability decreases with soil age and potentially limits the productivity of ecosystems growing on old and weathered soils. Despite growing on ancient soils, ecosystems of lowland Amazonia are highly productive and are among the most biodiverse on Earth. P eroded and weathered in the Andes is transported by the rivers and deposited in floodplains of the lowland Amazon basin creating hotspots of P fertility. We hypothesize that animals feeding on vegetation and detritus in these hotspots may redistribute P to P-depleted areas, thus contributing to dissipate the P gradient across the landscape. Using a mathematical model, we show that animal-driven spatial redistribution of P from rivers to land and from seasonally flooded to terra firme (upland ecosystems may sustain the P cycle of Amazonian lowlands. Our results show how P imported to land by terrestrial piscivores in combination with spatial redistribution of herbivores and detritivores can significantly enhance the P content in terra firme ecosystems, thereby highlighting the importance of food webs for the biogeochemical cycling of Amazonia.

  5. Evaluating the effect of nutrient redistribution by animals on the phosphorus cycle of lowland Amazonia

    Science.gov (United States)

    Buendía, Corina; Kleidon, Axel; Manzoni, Stefano; Reu, Björn; Porporato, Amilcare

    2018-01-01

    Phosphorus (P) availability decreases with soil age and potentially limits the productivity of ecosystems growing on old and weathered soils. Despite growing on ancient soils, ecosystems of lowland Amazonia are highly productive and are among the most biodiverse on Earth. P eroded and weathered in the Andes is transported by the rivers and deposited in floodplains of the lowland Amazon basin creating hotspots of P fertility. We hypothesize that animals feeding on vegetation and detritus in these hotspots may redistribute P to P-depleted areas, thus contributing to dissipate the P gradient across the landscape. Using a mathematical model, we show that animal-driven spatial redistribution of P from rivers to land and from seasonally flooded to terra firme (upland) ecosystems may sustain the P cycle of Amazonian lowlands. Our results show how P imported to land by terrestrial piscivores in combination with spatial redistribution of herbivores and detritivores can significantly enhance the P content in terra firme ecosystems, thereby highlighting the importance of food webs for the biogeochemical cycling of Amazonia.

  6. The Changing Seasonality of Tundra Nutrient Cycling: Implications for Arctic Ecosystem Function

    Science.gov (United States)

    Weintraub, M. N.; Steltzer, H.; Sullivan, P.; Schimel, J.; Wallenstein, M. D.; Darrouzet-Nardi, A.; Segal, A. D.

    2011-12-01

    Arctic soils contain large stores of carbon (C) and may act as a significant CO2 source with warming. However, the key to understanding tundra soil processes is nitrogen (N), as both plant growth and decomposition are N limited. However, current models of tundra ecosystems assume that while N limits plant growth, C limits decomposition. In addition, N availability is strongly seasonal with relatively high concentrations early in the growing season followed by a pronounced crash. We need to understand the controls on this seasonality to predict responses to climate change, but there are multiple questions that need answers: 1) What causes the seasonality in N? 2) Does microbial activity switch seasonally between C and N limitation? 3) How will a lengthening of the growing season alter overall ecosystem C and N dynamics, as a result of differential extension of the periods before and after the nutrient crash? We hypothesized that microbial activity is C limited early in the growing season, when N availability is higher and root exudate C is unavailable, and that microbial activity becomes N limited in response to plant N uptake and immobilization stimulated by root C. To address these questions we are conducting an accelerated snow-melt X warming field experiment in an Alaskan moist acidic arctic tundra community, and following plant and soil dynamics. Changes in the timing of C and N interactions in the different treatments will enable us to develop an enhanced mechanistic understanding of why the nutrient crash occurs and what the implications are for a lengthening of the arctic growing season. In 2010 we successfully accelerated snowmelt by 4 days. Both earlier snowmelt and warming accelerated early season plant life history events, with a few exceptions. However, responses to the combined treatment could not always be predicted from single factor effects. End of season life history events occurred later in response to the treatments, again with a few exceptions

  7. Ediacaran biota from Sonora, Mexico.

    OpenAIRE

    McMenamin, M A

    1996-01-01

    The Ediacaran biota is the earliest diverse community of macroscopic animals and protoctists. Body and trace fossils in the Clemente Formation of northwestern Sonora extend downward the geologic range of Ediacaran forms. Taxa present in the Clemente Formation include cf. Cyclomedusa plana, Sekwia sp., an erniettid (bearing an air mattress-like "pneu" body construction), and the trace fossils Lockeia ichnosp. and Palaeophycus tubularis. The trace fossils confirm the presence of sediment-dwelli...

  8. Calcium oxalate contribution to calcium cycling in forests of contrasting nutrient status

    Science.gov (United States)

    Dauer, Jenny M.; Perakis, Steven S.

    2014-01-01

    Calcium oxalate (Ca oxalate) is an insoluble biomineral that forms in plants and fungi, and occurs in soils across many types of ecosystems. Assessing how Ca oxalate may shape ecosystem Ca cycling requires information on the distribution of Ca oxalate among plant biomass, detritus, and mineral soil, and how it varies with ecosystem Ca status. We compared two Douglas-fir forests of contrasting ecosystem Ca availability, and found that Ca oxalate was partitioned similarly among plant biomass, detritus and mineral soil major ecosystem compartments at both sites, and total pools of Ca oxalate were greater in the high-Ca forest. However, the proportional importance of Ca oxalate was greater in the low-Ca than high-Ca forest (18% versus 4% of actively cycling ecosystem Ca, respectively). And calcium oxalate in mineral soil, which is of particular interest as a potential long-term Ca reservoir, was a larger portion of total available Ca (exchangeable Ca plus Ca oxalate Ca) in the low-Ca site than the high-Ca site (9% versus 1% of available soil Ca, respectively). Calcium oxalate was the dominant form of Ca returned from plants to soil as leaf litterfall at the high-Ca site, yet calcium oxalate disappeared rapidly from decomposing litter (0.28 yr−1 or faster) at both sites. We conclude that accumulation of Ca oxalate in forest ecosystems appears most closely related to overall Ca supply for live biomass pools, and that the accumulation of Ca oxalate in forest floor and mineral soil is limited by rapid microbial degradation of putatively unavailable Ca oxalate.

  9. Differential response of carbon cycling to long-term nutrient input and altered hydrological conditions in a continental Canadian peatland

    Science.gov (United States)

    Berger, Sina; Praetzel, Leandra S. E.; Goebel, Marie; Blodau, Christian; Knorr, Klaus-Holger

    2018-02-01

    Peatlands play an important role in global carbon cycling, but their responses to long-term anthropogenically changed hydrologic conditions and nutrient infiltration are not well known. While experimental manipulation studies, e.g., fertilization or water table manipulations, exist on the plot scale, only few studies have addressed such factors under in situ conditions. Therefore, an ecological gradient from the center to the periphery of a continental Canadian peatland bordering a eutrophic water reservoir, as reflected by increasing nutrient input, enhanced water level fluctuations, and increasing coverage of vascular plants, was used for a case study of carbon cycling along a sequence of four differently altered sites. We monitored carbon dioxide (CO2) and methane (CH4) surface fluxes and dissolved inorganic carbon (DIC) and CH4 concentrations in peat profiles from April 2014 through September 2015. Moreover, we studied bulk peat and pore-water quality and we applied δ13C-CH4 and δ13C-CO2 stable isotope abundance analyses to examine dominant CH4 production and emission pathways during the growing season of 2015. We observed differential responses of carbon cycling at the four sites, presumably driven by abundances of plant functional types and vicinity to the reservoir. A shrub-dominated site in close vicinity to the reservoir was a comparably weak sink for CO2 (in 1.5 years: -1093 ± 794, in 1 year: +135 ± 281 g CO2 m-2; a net release) as compared to two graminoid-moss-dominated sites and a moss-dominated site (in 1.5 years: -1552 to -2260 g CO2 m-2, in 1 year: -896 to -1282 g CO2 m-2). Also, the shrub-dominated site featured notably low DIC pore-water concentrations and comparably 13C-enriched CH4 (δ13C- CH4: -57.81 ± 7.03 ‰) and depleted CO2 (δ13C-CO2: -15.85 ± 3.61 ‰) in a more decomposed peat, suggesting a higher share of CH4 oxidation and differences in predominant methanogenic pathways. In comparison to all other sites, the graminoid

  10. Environmental impacts of innovative dairy farming systems aiming at improved internal nutrient cycling: A multi-scale assessment.

    Science.gov (United States)

    de Vries, W; Kros, J; Dolman, M A; Vellinga, Th V; de Boer, H C; Gerritsen, A L; Sonneveld, M P W; Bouma, J

    2015-12-01

    Several dairy farms in the Netherlands aim at reducing environmental impacts by improving the internal nutrient cycle (INC) on their farm by optimizing the use of available on-farm resources. This study evaluates the environmental performance of selected INC farms in the Northern Friesian Woodlands in comparison to regular benchmark farms using a Life Cycle Assessment. Regular farms were selected on the basis of comparability in terms of milk production per farm and per hectare, soil type and drainage conditions. In addition, the environmental impacts of INC farming at landscape level were evaluated with the integrated modelling system INITIATOR, using spatially explicit input data on animal numbers, land use, agricultural management, meteorology and soil, assuming that all farms practised the principle of INC farming. Impact categories used at both farm and landscape levels were global warming potential, acidification potential and eutrophication potential. Additional farm level indicators were land occupation and non-renewable energy use, and furthermore all farm level indicators were also expressed per kg fat and protein corrected milk. Results showed that both on-farm and off-farm non-renewable energy use was significantly lower at INC farms as compared with regular farms. Although nearly all other environmental impacts were numerically lower, both on-farm and off-farm, differences were not statistically significant. Nitrogen losses to air and water decreased by on average 5 to 10% when INC farming would be implemented for the whole region. The impact of INC farming on the global warming potential and eutrophication potential was, however, almost negligible (cycle. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Inferred effects of cloud deposition on forest floor nutrient cycling and microbial properties along a short elevation gradient

    International Nuclear Information System (INIS)

    Lavoie, M.; Bradley, R.L.

    2003-01-01

    variability of nutrient cycles and microbial properties

  12. Iron-dependent nitrogen cycling in a ferruginous lake and the nutrient status of Proterozoic oceans

    Science.gov (United States)

    Michiels, Céline C.; Darchambeau, François; Roland, Fleur A. E.; Morana, Cédric; Llirós, Marc; García-Armisen, Tamara; Thamdrup, Bo; Borges, Alberto V.; Canfield, Donald E.; Servais, Pierre; Descy, Jean-Pierre; Crowe, Sean A.

    2017-01-01

    Nitrogen limitation during the Proterozoic has been inferred from the great expanse of ocean anoxia under low-O2 atmospheres, which could have promoted NO3- reduction to N2 and fixed N loss from the ocean. The deep oceans were Fe rich (ferruginous) during much of this time, yet the dynamics of N cycling under such conditions remain entirely conceptual, as analogue environments are rare today. Here we use incubation experiments to show that a modern ferruginous basin, Kabuno Bay in East Africa, supports high rates of NO3- reduction. Although 60% of this NO3- is reduced to N2 through canonical denitrification, a large fraction (40%) is reduced to NH4+, leading to N retention rather than loss. We also find that NO3- reduction is Fe dependent, demonstrating that such reactions occur in natural ferruginous water columns. Numerical modelling of ferruginous upwelling systems, informed by our results from Kabuno Bay, demonstrates that NO3- reduction to NH4+ could have enhanced biological production, fuelling sulfate reduction and the development of mid-water euxinia overlying ferruginous deep oceans. This NO3- reduction to NH4+ could also have partly offset a negative feedback on biological production that accompanies oxygenation of the surface ocean. Our results indicate that N loss in ferruginous upwelling systems may not have kept pace with global N fixation at marine phosphorous concentrations (0.04-0.13 μM) indicated by the rock record. We therefore suggest that global marine biological production under ferruginous ocean conditions in the Proterozoic eon may thus have been P not N limited.

  13. Dynamic changes of nutrient composition throughout the entire life cycle of black soldier fly.

    Directory of Open Access Journals (Sweden)

    Xiu Liu

    Full Text Available Black soldier fly (BSF larvae, Hermetia illucens L., develops on organic wastes, reducing ecological pollution and converting waste biomass into protein and fat rich insect biomass. BSF can replace increasingly expensive protein sources used in poultry, aquaculture and livestock compound diet formulation, such as fish meal and soybean meal, which holds the potential to alleviate future food and feed insecurity. The fate of nutritional spectra in BSF during its life cycle phases is still poorly understood. This study assessed metabolic changes in nutrition composition of BSF from egg to adult. A rapid increase of crude fat content was observed since the development of 4-14 days of larvae with its maximum level reaching 28.4% in dry mass, whereas the crude protein displayed a continuous decreasing trend in the same development phases with minimum level of 38% at larval phase (12 days and peak level of 46.2% at early pupa stage. A sharp drop in crude fat was noticed from early prepupae to late pupae (24.2%, 8.2% respectively. However crude protein shows its maximum value being 57.6% at postmortem adult stage with 21.6% fat level. In addition, fatty acids, amino acids, minerals and vitamins composition in different development stages of BSF were presented and compared. Findings from this study could provide podium to food and feed industry for framing a strategy for specific molecular nutritional component intake into the diets of humans, aquaculture and animals. It is also indicated that BSF is a possible insect which can be applied to combating the food scarcity of countries where micronutrient deficiency is prevalent. Moreover it contributes to advance exploring for developmental and metabolic biology of this edible insect.

  14. Bacterial active community cycling in response to solar radiation and their influence on nutrient changes in a high altitude wetland

    Directory of Open Access Journals (Sweden)

    Veronica Molina

    2016-11-01

    Full Text Available Microbial communities inhabiting high altitude spring ecosystems are subjected to extreme changes in irradiation and temperature throughout the diel cycle. Here, using 16S rRNA gene tag pyrosequencing (cDNA we determined the composition of actively transcribing bacteria from spring waters experimentally exposed through the day (morning, noon and afternoon to variable levels of solar radiation and light quality, and evaluated their influence on nutrient recycling. Irradiation, temperature and changes in nutrient dynamics were associated with changes in the active bacterial community structure, predominantly by Cyanobacteria, Verrucomicrobia, Proteobacteria, and 35 other Phyla, including the recently described Candidate Phyla Radiation (e.g., Parcubacteria, Gracilibacteria, OP3, TM6, SR1. Diversity increased at noon, when the highest irradiances were measured (3.3 -3.9 H’, 1125 W m-2 compared to morning and afternoon (0.6-2.8 H’. This shift was associated with a decrease in the contribution to pyrolibraries by Cyanobacteria and an increase of Proteobacteria and other initially low frequently and rare bacteria phyla (<0.5% in the pyrolibraries. A potential increase in the activity of Cyanobacteria and other phototrophic groups, e.g., Rhodobacterales, was observed and associated with UVR, suggesting the presence of photo-activated repair mechanisms to resist high levels of solar radiation. In addition, the percentage contribution of cyanobacterial sequences in the afternoon was similar to those recorded in the morning. The shifts in the contribution by Cyanobacteria also influenced the rate of change in nitrate, nitrite and phosphate, highlighted by a high level of nitrate accumulation during hours of high radiation and temperature associated with nitrifying bacteria activity. We did not detect ammonia or nitrite oxidizing bacteria in-situ, but both functional groups (Nitrosomona and Nitrospira appeared mainly in pyrolibraries generated from

  15. Impact of simulated atmospheric nitrogen deposition on nutrient cycling and carbon sink via mycorrhizal fungi in two nutrient-poor peatlands

    Science.gov (United States)

    Larmola, Tuula; Kiheri, Heikki; Bubier, Jill L.; van Dijk, Netty; Dise, Nancy; Fritze, Hannu; Hobbie, Erik A.; Juutinen, Sari; Laiho, Raija; Moore, Tim R.; Pennanen, Taina

    2017-04-01

    Peatlands store one third of the global soil carbon (C) pool. Long-term fertilization experiments in nutrient-poor peatlands showed that simulated atmospheric nitrogen (N) deposition does not enhance ecosystem C uptake but reduces C sink potential. Recent studies have shown that a significant proportion of C input to soil in low-fertility forests entered the soil through mycorrhizal fungi, rather than as plant litter. Is atmospheric N deposition diminishing peatland C sink potential due to the suppression of ericoid mycorrhizal fungi? We studied how nutrient addition influences plant biomass allocation and the extent to which plants rely on mycorrhizal N uptake at two of the longest-running nutrient addition experiments on peatlands, Whim Bog, United Kingdom, and Mer Bleue Bog, Canada. We determined the peak growing season aboveground biomass production and coverage of vascular plants using the point intercept method. We also analyzed isotopic δ15N patterns and nutrient contents in leaves of dominant ericoid mycorrhizal shrubs as well as the non-mycorrhizal sedge Eriophorum vaginatum under different nutrient addition treatments. The treatments receive an additional load of 1.6-6.4 N g m-2 y-1 either as ammonium (NH4) nitrate (NO3) or NH4NO3 and with or without phosphorus (P) and potassium (K), alongside unfertilized controls. After 11-16 years of nutrient addition, the vegetation structure had changed remarkably. Ten of the eleven nutrient addition treatments showed an increase of up to 60% in total vascular plant abundance. Only three (NH4Cl, NH4ClPK, NaNO3PK) of the nutrient addition treatments showed a concurrent decrease of down to 50% in the relative proportion of ericoid mycorrhizal shrubs to total vascular plant abundance. The response to nutrient load may be explained by the water table depth, the form of N added and whether N was added with PK. Shrubs were strong competitors at the dry Mer Bleue bog while sedges gained in abundance at the wetter Whim bog

  16. Exploring the effects of black mangrove (Avicennia germinans) expansions on nutrient cycling in smooth cordgrass (Spartina alterniflora) marsh sediments of southern Louisiana, USA

    Science.gov (United States)

    Henry, K. M.; Twilley, R. R.

    2011-12-01

    Located at the northernmost extent of mangroves in the Gulf of Mexico, coastal Louisiana (LA) provides an excellent opportunity to study the effects of a climate-induced vegetation shift on nutrient cycling within an ecosystem. Climate throughout the Gulf Coast region is experiencing a general warming trend and scientists predict both hotter summers (+1.5 to 4 °C) and warmer winters (+1.5 to 5.5 °C) by 2100. Over the last two decades, mild winter temperatures have facilitated the expansion of black mangrove trees (Avicennia germinans) into the smooth cordgrass (Spartina alterniflora) along parts of the LA coast. Due to differences in morphology and physiology between these two species, the expansion of Avicennia has the potential to greatly alter sediment biogeochemistry, especially nutrient cycling. With such an extensive history of coastal nutrient enrichment and eutrophication in the Mississippi River delta, it is important to understand how nutrient cycling, retention, and removal in this region will be affected by this climate-induced vegetation expansion. We examined the effect of this species shift on porewater salinity, sulfide, and dissolved inorganic nutrient concentrations (nitrite, nitrate, ammonium, and phosphate) as well as sediment oxidation-reduction potential, bulk density, and nutrient content (carbon, nitrogen, phosphorus). We also measured net dinitrogen (N2:Ar), oxygen, and dissolved inorganic nutrient fluxes on intact, non-vegetated sediment cores collected from both Spartina and Avicennia habitats. Spartina sediments were more reducing, with higher concentrations of sulfides and ammonium. We found no significant difference between Spartina and Avicennia sediment dinitrogen, oxygen, or dissolved inorganic nutrient fluxes. Net dinitrogen fluxes for both habitat types were predominately positive, indicating higher rates of denitrification than nitrogen fixation at these sites. Sediments were primarily a nitrate sink, but functioned as both a

  17. Context-dependent consequences of Marenzelleria spp. (Spionidae: Polychaeta invasion for nutrient cycling in the Northern Baltic Sea

    Directory of Open Access Journals (Sweden)

    Alexey Maximov

    2015-10-01

    Full Text Available Marenzelleria spp. are among the most successful non-native benthic species in the Baltic Sea. These burrowing polychaetes dig deeper than most native Baltic species, performing previously lacking ecosystem functions. We examine evidence from experiments, field sampling and modelling that the introduction of Marenzelleria spp. affects nutrient cycling and biogeochemical processes at the sediment–water interface. Over longer time scales, bioirrigation by Marenzelleria spp. has the potential to increase phosphorus retention in bottom deposits because of deeper oxygen penetration into sediments and formation of a deeper oxidized layer. In contrast, nitrogen fluxes from the sediment increase. As a consequence of a decline of the phosphate concentration and/or rising nitrogen/phosphorus ratio, some Northern Baltic ecosystems may experience improvement of the environment because of mitigation of eutrophication and harmful cyanobacteria blooms. Although it is difficult to unambiguously estimate the ecosystem-level consequences of invasion, in many cases it could be considered as positive due to increased structural and functional diversity. The long-term interactions with the native fauna still remain unknown, however, and in this paper we highlight the major knowledge gaps.

  18. Ciclagem de nutrientes por plantas de cobertura na entressafra em um solo de cerrado Nutrient cycling in off-season cover crops on a Brazilian savanna soil

    Directory of Open Access Journals (Sweden)

    Carlo Adriano Boer

    2007-09-01

    Full Text Available O objetivo deste trabalho foi avaliar o acúmulo e a liberação de nutrientes (N, P, K, Ca, Mg e S de resíduos culturais de plantas de cobertura na entressafra, em condições de Cerrado. O experimento foi conduzido em um Latossolo Vermelho distroférrico com textura argilosa. As plantas de cobertura avaliadas foram: amaranto (Amaranthus cruentus L., milheto (Pennisetum glaucum L. e capim-pé-de-galinha (Eleusine coracana (L. Gaertn.. O delineamento experimental utilizado foi o de blocos ao acaso, no esquema de parcelas subdivididas, com quatro repetições. Na fase de florescimento das espécies, foi avaliada a produção de matéria seca e o acúmulo de nutrientes. A fim de avaliar a liberação de nutrientes dos resíduos culturais, o material vegetal de cada espécie foi acondicionado em sacolas de náilon, as quais foram dispostas sobre o solo e seu conteúdo analisado em intervalos de 30 dias, até 240 dias após sua instalação. As maiores quantidades de nutrientes acumulados na fitomassa das plantas de cobertura foram observadas no milheto e no capim-pé-de-galinha. O potássio foi o nutriente acumulado em maior quantidade, chegando a atingir 416,9 kg ha-1 no milheto. As maiores taxas de liberação de nutrientes foram observadas nos resíduos culturais do amaranto.The objective of this work was to evaluate the accumulation and the liberation of nutrients (N, P, K, Ca, Mg and S of cultural residues by three species of cover crops, in off-season. Tested cover crops were amaranthus (Amaranthus cruentus L., pearl millet (Pennisetum glaucum L. and finger millet (Eleusine coracana (L. Gaertn.. The experiment was carried out in a Typic Haplorthox clay texture soil. A randomized block desing in a split-plot array in time, with four replications, was used. At the flowering of the species, the production of dry matter and the accumulation of nutrients were evaluated. Proportional samples of dry matter of each cover crop species were placed in

  19. Differences in ecosystem carbon distribution and nutrient cycling linked to forest tree species composition in a mid-successional boreal forest

    Science.gov (United States)

    Melvin, April M.; Mack, Michelle C.; Johnstone, Jill F.; McGuire, A. David; Genet, Helene; Schuur, Edward A.G.

    2015-01-01

    In the boreal forest of Alaska, increased fire severity associated with climate change is expanding deciduous forest cover in areas previously dominated by black spruce (Picea mariana). Needle-leaf conifer and broad-leaf deciduous species are commonly associated with differences in tree growth, carbon (C) and nutrient cycling, and C accumulation in soils. Although this suggests that changes in tree species composition in Alaska could impact C and nutrient pools and fluxes, few studies have measured these linkages. We quantified C, nitrogen, phosphorus, and base cation pools and fluxes in three stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a single fire event in 1958. Paper birch consistently displayed characteristics of more rapid C and nutrient cycling, including greater aboveground net primary productivity, higher live foliage and litter nutrient concentrations, and larger ammonium and nitrate pools in the soil organic layer (SOL). Ecosystem C stocks (aboveground + SOL + 0–10 cm mineral soil) were similar for the two species; however, in black spruce, 78% of measured C was found in soil pools, primarily in the SOL, whereas aboveground biomass dominated ecosystem C pools in birch forest. Radiocarbon analysis indicated that approximately one-quarter of the black spruce SOL C accumulated prior to the 1958 fire, whereas no pre-fire C was observed in birch soils. Our findings suggest that tree species exert a strong influence over C and nutrient cycling in boreal forest and forest compositional shifts may have long-term implications for ecosystem C and nutrient dynamics.

  20. Dissolved organic matter and lake metabolism: Biogeochemistry and controls of nutrient flux dynamics to fresh waters. Technical progress report, January 1, 1990--December 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, R.G.

    1992-12-31

    The land-water interface region consists of two major components: the wetland, and the down-gradient adjacent littoral floating-leaved and submersed, macrophyte communities. Because of the importance of very high production and nutrient turnover of attached microbiota, a major emphasis of this investigation was placed upon these biota and their metabolic capacities for assimilation and release of organic compounds and nutrient retention and cycling. Examination of the capacities of wetland littoral communities to regulate fluxes of nutrients and organic compounds often has been limited to input-output analyses. These input-output data are an integral part of these investigations, but most of the research effort concentrated on the biotic and metabolic mechanisms that control fluxes and retention capacities and their effects upon biota in the down-gradient waters. The important regulatory capacities of dissolved organic compounds on enzyme reactivity was examined experimentally and coupled to the wetland-littoral organic carbon flux budgets.

  1. Ammonium and nitrate uptake lengths in a small forested stream determined by {sup 15}N tracer and short-term nutrient enrichment experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, P.J.; Tank, J.L.; Sanzone, D.M.; Webster, J.R.; Wollheim, W.; Peterson, B.J.; Meyer, J.L.

    1998-11-01

    Nutrient cycling is an important characteristic of all ecosystems, including streams. Nutrients often limit the growth rates of stream algae and heterotrophic microbes and the decomposition rate of allochthonous organic matter. Nutrient uptake (S{sub W}), defined as the mean distance traveled by a nutrient atom dissolved in stream water before uptake by biota is often used as an index of nutrient cycling in streams. It is often overlooked, however, that S{sub W} is not a measure of nutrient uptake rate per se, but rather a measure of the efficiency with which a stream utilizes the available nutrient supply. The ideal method for measuring S{sub W} involves short-term addition of a nutrient tracer. Regulatory constraints often preclude use of nutrient radiotracers in field studies and methodological difficulties and high analytical costs have previously hindered the use of stable isotope nutrient tracers (e.g., {sup 15}N). Short-term nutrient enrichments are an alternative to nutrient tracer additions for measuring S{sub W}.

  2. Identifying the impacts of land use on water and nutrient cycling in the South-West Mau, Kenya

    Science.gov (United States)

    Jacobs, Suzanne; Weeser, Björn; Breuer, Lutz; Butterbach-Bahl, Klaus; Rufino, Mariana

    2016-04-01

    The Mau Forest is the largest closed canopy forest system and indigenous montane forest in Kenya, covering approximately 400,000 ha. It is the source of twelve major rivers in the Rift Valley and Western Kenya and one of Kenya's five 'water towers' that provide around 10 million people with fresh water. Significant areas have been affected by deforestation and land use changes in the past decades, resulting in a loss of approx. 25% of the forest area. Recent changes in downstream water supply are discussed to be attributed to land use change, though compelling scientific evidence is still lacking. The study area is located in the South-West Mau as a part of the Sondu River basin that drains into Lake Victoria. This area has suffered a forest loss of 25% through conversion of natural forest to smallholder agriculture and tea/tree plantations. A nested catchment approach has been applied, whereby automatic measurement equipment for monitoring discharge, turbidity, nitrate, total and dissolved organic carbon, electrical conductivity and water temperature at a 10 minute interval has been set up at the outlets of three sub-catchments of 27 - 36 km² and the outlet of the 1023 km² major catchment. The dominant land use in the sub-catchments is either natural forest, tea/tree plantation or smallholder agriculture. The river data is complemented by six precipitation gauging stations and three climate stations, that all measure at the same interval. Installed during October 2014, the systems have collected high resolution data for one and a half year now. The high resolution dataset is being analysed for patterns in stream flow and water quality during dry and wet seasons as well as diurnal cycling of nitrate. The results of the different sub-catchments are compared to identify the role of land use in water and nutrient cycling. First results of the high temporal resolution data already indicate that the different types of land use affect the stream nitrate concentration

  3. Nutrient Cycling and Retention Along a Littoral Gradient in a Dutch Shallow Lake in Relation to Water Level Regime

    NARCIS (Netherlands)

    Sollie, S.; Verhoeven, J.T.A.

    Littoral zones are characterized by gradients in depth and vegetation biomass, influencing nutrient retention capacity. A field experiment was conducted in a Phragmites australis dominated littoral zone to investigate nutrient retention and its effect on surface water quality. Measurements were done

  4. Timing of initiation of macronuclear DNA synthesis is set during the preceding cell cycle in Paramecium tetraurelia: analysis of the effects of abrupt changes in nutrient level

    Energy Technology Data Exchange (ETDEWEB)

    Ching, A.S.L.; Berger, J.D.

    1986-11-01

    In many eukaryotic organisms, initiation of DNA synthesis is associated with a major control point within the cell cycle and reflects the commitment of the cell to the DNA replication-division portion of the cell cycle. In paramecium, the timing of DNA synthesis initiation is established prior to fission during the preceding cell cycle. DNA synthesis normally starts at 0.25 in the cell cycle. When dividing cells are subjected to abrupt nutrient shift-up by transfer from a chemostat culture to medium with excess food, or shift-down from a well-fed culture to exhausted medium, DNA synthesis initiation in the post-shift cell cycle occurs at 0.25 of the parental cell cycle and not at either 0.25 in the post-shift cell cycle or at 0.25 in the equilibrium cell cycle produced under the post-shift conditions. The long delay prior to initiation of DNA synthesis following nutritional shift-up is not a consequence of continued slow growth because the rate of protein synthesis increases rapidly to the normal level after shift-up. Analysis of the relation between increase in cell mass and initiation of DNA synthesis following nutritional shifts indicates that increase in cell mass, per se, is neither a necessary nor a sufficient condition for initiation of DNA synthesis, in spite of the strong association between accumulation of cell mass and initiation of DNA synthesis in cells growing under steady-state conditions.

  5. Timing of initiation of macronuclear DNA synthesis is set during the preceding cell cycle in Paramecium tetraurelia: analysis of the effects of abrupt changes in nutrient level

    International Nuclear Information System (INIS)

    Ching, A.S.L.; Berger, J.D.

    1986-01-01

    In many eukaryotic organisms, initiation of DNA synthesis is associated with a major control point within the cell cycle and reflects the commitment of the cell to the DNA replication-division portion of the cell cycle. In paramecium, the timing of DNA synthesis initiation is established prior to fission during the preceding cell cycle. DNA synthesis normally starts at 0.25 in the cell cycle. When dividing cells are subjected to abrupt nutrient shift-up by transfer from a chemostat culture to medium with excess food, or shift-down from a well-fed culture to exhausted medium, DNA synthesis initiation in the post-shift cell cycle occurs at 0.25 of the parental cell cycle and not at either 0.25 in the post-shift cell cycle or at 0.25 in the equilibrium cell cycle produced under the post-shift conditions. The long delay prior to initiation of DNA synthesis following nutritional shift-up is not a consequence of continued slow growth because the rate of protein synthesis increases rapidly to the normal level after shift-up. Analysis of the relation between increase in cell mass and initiation of DNA synthesis following nutritional shifts indicates that increase in cell mass, per se, is neither a necessary nor a sufficient condition for initiation of DNA synthesis, in spite of the strong association between accumulation of cell mass and initiation of DNA synthesis in cells growing under steady-state conditions

  6. Anthropogenic influences on the input and biogeochemical cycling of nutrients and mercury in Great Salt Lake, Utah, USA

    International Nuclear Information System (INIS)

    Naftz, David; Angeroth, Cory; Kenney, Terry; Waddell, Bruce; Darnall, Nathan; Silva, Steven; Perschon, Clay; Whitehead, John

    2008-01-01

    Despite the ecological and economic importance of Great Salt Lake (GSL), little is known about the input and biogeochemical cycling of nutrients and trace elements in the lake. In response to increasing public concern regarding anthropogenic inputs to the GSL ecosystem, the US Geological Survey (USGS) and US Fish and Wildlife Service (USFWS) initiated coordinated studies to quantify and evaluate the significance of nutrient and Hg inputs into GSL. A 6 per mille decrease in δ 15 N observed in brine shrimp (Artemia franciscana) samples collected from GSL during summer time periods is likely due to the consumption of cyanobacteria produced in freshwater bays entering the lake. Supporting data collected from the outflow of Farmington Bay indicates decreasing trends in δ 15 N in particulate organic matter (POM) during the mid-summer time period, reflective of increasing proportions of cyanobacteria in algae exported to GSL on a seasonal basis. The C:N molar ratio of POM in outflow from Farmington Bay decreases during the summer period, supportive of the increased activity of N fixation indicated by decreasing δ 15 N in brine shrimp and POM. Although N fixation is only taking place in the relatively freshwater inflows to GSL, data indicate that influx of fresh water influences large areas of the lake. Separation of GSL into two distinct hydrologic and geochemical systems from the construction of a railroad causeway in the late 1950s has created a persistent and widespread anoxic layer in the southern part of GSL. This anoxic layer, referred to as the deep brine layer (DBL), has high rates of SO 4 2- reduction, likely increasing the Hg methylation capacity. High concentrations of methyl mercury (CH 3 Hg) (median concentration = 24 ng/L) were observed in the DBL with a significant proportion (31-60%) of total Hg in the CH 3 Hg form. Hydroacoustic and sediment-trap evidence indicate that turbulence introduced by internal waves generated during sustained wind events can

  7. Anthropogenic influences on the input and biogeochemical cycling of nutrients and mercury in Great Salt Lake, Utah, USA

    Energy Technology Data Exchange (ETDEWEB)

    Naftz, David [US Geological Survey, Salt Lake City 84119, UT (United States)], E-mail: dlnaftz@usgs.gov; Angeroth, Cory; Kenney, Terry [US Geological Survey, Salt Lake City 84119, UT (United States); Waddell, Bruce; Darnall, Nathan [US Fish and Wildlife Service, Salt Lake City, UT (United States); Silva, Steven [US Geological Survey, Menlo Park, CA (United States); Perschon, Clay [Utah Division of Wildlife Resources, Salt Lake City, UT (United States); Whitehead, John [Utah Department of Environmental Quality, Salt Lake City, UT (United States)

    2008-06-15

    Despite the ecological and economic importance of Great Salt Lake (GSL), little is known about the input and biogeochemical cycling of nutrients and trace elements in the lake. In response to increasing public concern regarding anthropogenic inputs to the GSL ecosystem, the US Geological Survey (USGS) and US Fish and Wildlife Service (USFWS) initiated coordinated studies to quantify and evaluate the significance of nutrient and Hg inputs into GSL. A 6 per mille decrease in {delta}{sup 15}N observed in brine shrimp (Artemia franciscana) samples collected from GSL during summer time periods is likely due to the consumption of cyanobacteria produced in freshwater bays entering the lake. Supporting data collected from the outflow of Farmington Bay indicates decreasing trends in {delta}{sup 15}N in particulate organic matter (POM) during the mid-summer time period, reflective of increasing proportions of cyanobacteria in algae exported to GSL on a seasonal basis. The C:N molar ratio of POM in outflow from Farmington Bay decreases during the summer period, supportive of the increased activity of N fixation indicated by decreasing {delta}{sup 15}N in brine shrimp and POM. Although N fixation is only taking place in the relatively freshwater inflows to GSL, data indicate that influx of fresh water influences large areas of the lake. Separation of GSL into two distinct hydrologic and geochemical systems from the construction of a railroad causeway in the late 1950s has created a persistent and widespread anoxic layer in the southern part of GSL. This anoxic layer, referred to as the deep brine layer (DBL), has high rates of SO{sub 4}{sup 2-} reduction, likely increasing the Hg methylation capacity. High concentrations of methyl mercury (CH{sub 3}Hg) (median concentration = 24 ng/L) were observed in the DBL with a significant proportion (31-60%) of total Hg in the CH{sub 3}Hg form. Hydroacoustic and sediment-trap evidence indicate that turbulence introduced by internal waves

  8. Nutrient Removal and Resource Recovery: Effect on Life Cycle Cost and Environmental Impacts of Small Scale Wastewater Treatment

    Science.gov (United States)

    Many communities across the U.S. are required to upgrade wastewater treatment plants (WWTP) to meet increasingly stringent nutrient effluent standards. However, increased capital, energy and chemical requirements of upgrades create potential trade-offs between eutrophication pote...

  9. Impact of atmospheric and physical forcings on biogeochemical cycling of dissolved oxygen and nutrients in the coastal Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Sridevi, B.; Maneesha, K.; Sridevi, T.; Naidu, S.A; Prasad, V.R.; Venkataramana, V.; Acharya, T.; Bharati, M; Subbaiah, C.V.; Kiran, B.S.; Reddy, N.P.C.; Sarma, V.V.; Sadhuram, Y.; Murty, T.V.R.

    Time-series observations were conducted off Visakhapatnam, central west coast of Bay of Bengal, from October 2007 to April 2009 to examine the influence of physical and atmospheric processes on water column nutrients biogeochemistry. The thermal...

  10. Proposed Release Guides to Protect Aquatic Biota

    Energy Technology Data Exchange (ETDEWEB)

    Marter, W.L.

    2001-03-28

    At the request of South Carolina Department of Health and Environmental Control (SCDHEC) and the Department of Energy (DOE), the Savannah River Laboratory was assigned the task of developing the release guides to protect aquatic biota. A review of aquatic radioecology literature by two leading experts in the field of radioecology concludes that exposure of aquatic biota at one rad per day or less will not produce detectable deleterious effects on aquatic organisms. On the basis of this report, DOE recommends the use of one rad per day as an interim dose standard to protect aquatic biota.

  11. Increased Intake of Foods with High Nutrient Density Can Help to Break the Intergenerational Cycle of Malnutrition and Obesity

    Directory of Open Access Journals (Sweden)

    Barbara Troesch

    2015-07-01

    Full Text Available A workshop held at the University Medical Center in Groningen, The Netherlands, aimed at discussing the nutritional situation of the population in general and the role diet plays during critical windows in the life course, during which the body is programmed for the development of non-communicable diseases (NCDs. NCDs are increasingly prevalent as our society ages, and nutrition is well known to play an important role in determining the risk and the time of onset of many common NCDs. Even in affluent countries, people have difficulties to achieve adequate intakes for a range of nutrients: Economic constraints as well as modern lifestyles lead people to consume diets with a positive energy balance, but low in micronutrients, resulting in increasing prevalence of obesity and suboptimal nutritional status. Information about nutrient density, which refers to the content of micronutrients relative to energy in food or diets, can help identify foods that have a low calorie to nutrient ratio. It thus allows the consumption of diets that cover nutritional needs without increasing the risk of becoming obese. Given the impact a nutrient dense, low energy diet can have on health, researchers, food industry and governments jointly should develop options for affordable, appealing nutrient-rich food products, which, in combination with physical activity, allow for optimal health throughout the life-course.

  12. Seasonal greenhouse gas and soil nutrient cycling in semi-arid native and non-native perennial grass pastures

    Science.gov (United States)

    Previous research indicates that a difference occurs in native and non-native grass species in regard to drivers of greenhouse gas (GHG, (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O))) emissions from soil. Drivers of soil nutrients could help establish best management practices to mit...

  13. Part 7: Monitoring of biota

    International Nuclear Information System (INIS)

    1997-01-01

    The present state of the biota, in respect to the previous state and in respect to the development after the realised technical measures on both sides, was evaluated according to the data included in the Slovak-Hungarian joint monitoring covering the period from 1992 to 1996. The river branch water supply on the Slovak side was introduced in May 1993 through the intake structure at Dobrohost. On the Hungarian side the water supply is accomplished by the underwater weir put into operation in June 1995. The biological monitoring on the Slovak side was performed at six monitoring areas, where all the groups agreed in the joint monitoring were monitored. On the Hungarian side each group were monitored on different monitoring sites. The water supply introduced on the Hungarian side by the underwater weir operation has no impact on the Slovak side. Similar impact as it is now observed on the Hungarian side has been observed on the Slovak side since introduction of water supply in 1993. The increased amount of water discharged to the Danube was reflected by changes of the habitat of aquatic communities. The water supply on the Hungarian side was accomplished by the construction of the underwater weir and therefore a connection of the river branch system with the Danube at two factors have had very significant influence on the bio-tops existing in the river branch system and subsequently to the fauna and flora. Generally large amount of water became available, which was reflected in change of stagnant or slowly flowing water into water flow with higher velocity or in increase of the water surface. In some locations the water level returned to the state before damming, in others new bio-tops were created, and in some locations the previous bio-tops disappeared. To these changed conditions the aquatic fauna reacted the most rapidly.The terrestrial communities prove the necessity of flooding and raising of ground water level on some of the inundation areas, because in spite

  14. Biomass and nutrient cycling in pure and mixed stands of native tree species in southeastern Bahia, Brazil Biomassa e ciclagem de nutrientes por espécies florestais nativas em plantio puro e misto no sudeste da Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Antonio Carlos da Gama-Rodrigues

    2007-04-01

    Full Text Available The objective of this paper is to study selected components of the nutrient cycle of pure and mixed stands of native forest species of Atlantic Forest in southeastern Brazil. Tree diameter, height, above-ground biomass, and nutrient content were determined in 22-year-old stands. Litterfall, litter decomposition, and nutrient concentration were evaluated from August 1994 to July 1995. The following species were studied: Peltogyne angustiflora, Centrolobium robustum, Arapatiella psilophylla, Sclerolobium chrysophyllum, Cordia trichotoma, Macrolobium latifolium. The litter of a natural forest and a 40-year-old naturally regenerated second-growth forest was sampled as well. The mixed-species outmatched pure stands in height, stem volume and total biomass (29.4 % more. The greatest amount of forest litter was observed in the natural forest (9.3 Mg ha-1, followed by the mixed-species stand (7.6 Mg ha-1 and secondary forest (7.3 Mg ha-1, and least litterfall was measured in the pure C. robustum stand (5.5 Mg ha-1. Litterfall seasonality varied among species in pure stands (CV from 44.7 to 91.4 %, unlike litterfall in the mixed-tree stand, where the variation was lower (CV 31.2 %. In the natural and second-growth forest, litterfall varied by 57.8 and 34.0 %, respectively. The annual rate of nutrient return via litterfall varied widely among forest ecosystems. Differences were detected between forest ecosystems in both the litter accumulation and quantity of litterlayer nutrients. The highest mean nutrient accumulation in above-ground biomass was observed in mixed-species stands. The total nutrient accumulation (N + P + K+ Ca + Mg ranged from 0.97 to 1.93 kg tree-1 in pure stands, and from 1.21 to 2.63 kg tree-1 in mixed-species stands. Soil fertility under mixed-species stands (0-10 cm was intermediate between the primary forest and pure-stand systems. The litterfall rate of native forest species in a mixed-species system is more constant, resulting in

  15. Biogeochemical characterization of the Cointzio reservoir (Morelia, Mexico) and identification of a watershed-dependent cycling of nutrients

    Science.gov (United States)

    Némery, J.; Alvarado, R.; Gratiot, N.; Duvert, C.; Mahé, F.; Duwig, C.; Bonnet, M.; Prat, C.; Esteves, M.

    2009-12-01

    The Cointzio reservoir (capacity 70 Mm3) is an essential component of the drinking water supply (20 %) of Morelia city (1 M inhabitants, Michoacán, Mexico). The watershed is 627 km2 and mainly forested (45 %) and cultivated (43 %) with recent increase of avocados plantations. The mean population density is 65 inh./km2 and there are no waste water treatment plants in the villages leading locally to high levels of organic and nutritive pollution. Soils are mostly volcanic and recent deforestations have led to important processes of erosion especially during the wet season (from June to October). As a result the reservoir presents a high turbidity level (Secchi Del Agua (CNA). The water residence time in the reservoir is lower than one year. Nutrients fluxes entering and exiting the reservoir were calculated as the product of water discharges and weekly concentrations of nutrients. Within the reservoir, the vertical distributions of temperature, oxygen, turbidity, pH (with a Hydrolab probe), nutrients (PO43-, NH4+, NO3-), Dissolved Organic Carbon, chlorophyll a (laboratory analysis with a Hach Lange spectrophotometer), phytoplankton and zooplankton (variety and abundance) were measured every month to determine its seasonal dynamics. Samples of deposited sediments were also taken to assess phosphorus (P) stock. Nutrient inputs revealed to be strongly conditioned by the watershed hydrology. During low flow period (November to May), the baseflow is much more concentrated in dissolved nutrients. On the contrary, the high flows (June to October) bring a high amount of suspended sediments (up to 50g/L) that transport nutrients such as particulate P. Despite the high turbidity level of the reservoir, chlorophyll a concentrations appear important (70 µg/L during the dry season) especially in the first five meters of the water column. The phytoplankton community is dominated by Euglenophyta and Cyanobacteria groups typical of eutrophic waters. This study is the first

  16. Approaches and uncertainties in nutrient budgets; Implications for nutrient management and environmental policies

    NARCIS (Netherlands)

    Oenema, O.; Kros, J.; Vries, de W.

    2003-01-01

    Nutrient budgets of agroecosystems are constructed either (i) to increase the understanding of nutrient cycling, (ii) as performance indicator and awareness raiser in nutrient management and environmental policy, or (iii) as regulating policy instrument to enforce a certain nutrient management

  17. Changes in water mass exchange between the NW shelf areas and the North Atlantic and their impact on nutrient/carbon cycling

    Science.gov (United States)

    Gröger, Matthias; Maier-Reimer, Ernst; Mikolajewicz, Uwe; Segschneider, Joachim; Sein, Dimitry

    2010-05-01

    Despite their comparatively small extension on a global scale, shelf areas are of interest for several economic reasons and climatic processes related to nutrient cycling, sea food supply, and biological productivity. Moreover, they constitute an important interface for nutrients, pollutants and freshwater on their pathway from the continents to the open ocean. This modelling study aims to investigate the spatial and temporal variability of water mass exchange between the North Atlantic and the NW European shelf and their impact on nutrient/carbon cycling and biological productivity. For this, a new modeling approach has been set up which bridges the gap between pure shelf models where water mass transports across the model domain too strongly depend on the formulation of open boundaries and global models suffering under their too coarse resolution in shelf regions. The new model consists of the global ocean and carbon cycle model MPIOM/HAMOCC with strongly increased resolution in the North Sea and the North Atlantic coupled to the regional atmosphere model REMO. The model takes the full luni-solar tides into account. It includes further a 12 layer sediment module with the relevant pore water chemistry. The main focus lies on the governing mechanisms of water mass exchange across the shelf break and the imprint on shelf biogeochemistry. For this, artificial tracers with a prescribed decay rate have been implemented to distinguish waters arriving from polar and shelf regions and those that originate from the tropics. Experiments were carried out for the years 1948 - 2007. The relationship to larger scale circulation patterns like the position and variability of the subtropical and subpolar gyres is analyzed. The water mass exchange is analyzed with respect to the nutrient concentration and productivity on the European shelf areas. The implementation of tides leads to an enhanced vertical mixing which causes lower sea surface temperatures compared to simulations

  18. Martian base agriculture: The effect of low gravity on water flow, nutrient cycles, and microbial biomass dynamics

    Science.gov (United States)

    Maggi, Federico; Pallud, Céline

    2010-11-01

    The latest advances in bioregenerative strategies for long-term life support in extraterrestrial outposts such as on Mars have indicated soil-based cropping as an effective approach for waste decomposition, carbon sequestration, oxygen production, and water biofiltration as compared to hydroponics and aeroponics cropping. However, it is still unknown if cropping using soil systems could be sustainable in a Martian greenhouse under a gravity of 0.38 g. The most challenging aspects are linked to the gravity-induced soil water flow; because water is crucial in driving nutrient and oxygen transport in both liquid and gaseous phases, a gravitational acceleration lower than g = 9.806 m s -2 could lead to suffocation of microorganisms and roots, with concomitant emissions of toxic gases. The effect of Martian gravity on soil processes was investigated using a highly mechanistic model previously tested for terrestrial crops that couples soil hydraulics and nutrient biogeochemistry. Net leaching of NO3- solute, gaseous fluxes of NH 3, CO 2, N 2O, NO and N 2, depth concentrations of O 2, CO 2 and dissolved organic carbon (DOC), and pH in the root zone were calculated for a bioregenerative cropping unit under gravitational acceleration of Earth and for its homologous on Mars, but under 0.38 g. The two cropping units were treated with the same fertilizer type and rate, and with the same irrigation regime, but under different initial soil moisture content. Martian gravity reduced water and solute leaching by about 90% compared to Earth. This higher water holding capacity in soil under Martian gravity led to moisture content and nutrient concentrations that favoured the metabolism of various microbial functional groups, whose density increased by 5-10% on Mars as compared to Earth. Denitrification rates became substantially more important than on Earth and ultimately resulted in 60%, 200% and 1200% higher emissions of NO, N 2O and N 2 gases, respectively. Similarly, O 2 and DOC

  19. The impact of pasture conversion on nutrient cycles of tropical streams on the Osa Peninsula, Costa Rica: a paired catchment approach

    Science.gov (United States)

    Bringhurst, K.; Jordan, P.

    2011-12-01

    Changes in nutrient and hydrologic cycles caused by land disturbance typically lead to detrimental changes to ecosystems. This study utilized a paired, small-catchment approach to examine the effect of deforestation on nutrient transfer and hydrological discharge and the resulting impact on soils and streams of the Osa Peninsula, Costa Rica. Two first order streams were chosen, the first catchment had been cleared for pasture and the second consisted of undisturbed tropical wet forest. Soil concentrations of organic matter, total and soil available P were higher in the forested catchment with decreases of >33% of each in the deforested catchment. The effect of deforestation on stream discharge was a 59% increase in flow during the wet season and an increase in the Q5:Q95 ratio showing that the deforested stream was flashier. The deforested catchment loss of dissolved inorganic nitrogen (DIN) increased 95% over the forested catchment. Soluble reactive phosphorus (SRP) showed an increase in load of 43% in the deforested catchment compared to the forested catchment. The molar N:P ratios were lower than the Redfield ratio and both streams were well below the level at which N-limitation of lotic algal growth has been reported, therefore it is hypothesized that N is the limiting nutrient in streams in the study area. Soil nutrient depletion in the deforested catchment, accelerated by a changed hydrologic regime, is the likely trajectory of soil-water interactions in this tropical ecosystem. This will likely be among the secondary impacts should deforestation become widespread along this stretch of the Pacific coastline, with associated eutrophication of receiving transitional and coastal waters.

  20. Making sense of ocean biota: How evolution and biodiversity of land ...

    Indian Academy of Sciences (India)

    The oceans cover 70% of the planet's surface, and their planktonic inhabitants generate about half the global primary production, thereby playing a key role in modulating planetary climate via the carbon cycle. The ocean biota have been under scientific scrutiny for well over a century, and yet our understanding of the ...

  1. Bioaerosols in the Eastern Mediterranean: abundance, speciation, seasonality, impact on nutrient cycles and role of airmass and meteorology

    Science.gov (United States)

    Almpani, Chara; Negron, Arnaldo; Kanakidou, Maria; Mihalopoulos, Nikolaos; Nenes, Athanasios

    2017-04-01

    Primary biological aerosol particles (PBAPs) are a ubiquitous component of the atmosphere. They are studied in part to understand their unique role in cloud formation by acting as cloud condensation nuclei (CCN) and ice nuclei (IN) [1, 2], impacts on health and their role as nutrient supply for ocean ecosystems [3]. Little is known about the seasonal variability, lifecycle and survival mechanism in the atmosphere of PBAPs, in part due to challenges in available techniques for their detection. Our study aims to quantify the concentration of supermicron PBAPs at a remote marine ground site in the Eastern Mediterranean to help understand their potential impacts on cloud formation, and contribution to nutrient deposition to the surface ocean. Sampling took place in the Finokalia Station and in the city of Heraklion. Eight hour samples were collected using a Spincon II wet-walled cyclone sampler every two days over a 9-month period (May, 2016 - January 2017) and were subsequently analyzed using flow cytometry and epifluorescence microscopy protocols developed by Negron et al., 2017 [4]. Preliminary results show low biomass samples over Finokalia site and concentrations around 103 - 105 m-3, depending on the origin of the airmass. Further analysis of the samples focus on the influence of meteorological conditions on the relative abundance of bacteria, fungi, pollen, associated virues and biological debris. Estimates of the nutrient fluxes and the seasonality thereof are also provided, and compared against existing modeling estimates [3]. References: [1] Jaenicke, R. Science 308, 73. [2] Morris, C. E. et al., Glob Chang Biol 20(2): 341-351. [3] Myriokefalitakis et al., Biogeosciences, 13, 6519-6543 [4] Negron, A., et al., in preparation.

  2. Life cycle, secondary production and nutrient stock in Heleobia australis (d'Orbigny 1835) (Gastropoda: Hydrobiidae) in a tropical coastal lagoon

    Science.gov (United States)

    Figueiredo-Barros, Marcos P.; Leal, João J. F.; de A. Esteves, Francisco; de M. Rocha, Adriana; Bozelli, Reinaldo L.

    2006-08-01

    The aim of this research was to evaluate density, biomass, life cycle, secondary production and nutrient stock of Heleobia australis population (d'Orbigny 1835) in a coastal tropical lagoon (Imboassica lagoon). Carbon (C), nitrogen (N), phosphorus (P) and organic matter (OM) concentrations in the sediment were determined in order to evaluate their influence on the density, biomass and concentrations of C, N, P and OM in the biomass of H. australis population. Two sampling stations were established: one in the central part of the lagoon (station 1, not influenced directly by sewage release) and the second near the littoral region (station 2, close to the outlet of a canal discharging domestic sewage). Triplicate samples were collected monthly for one year (from May 1999 to April 2000) with a "core" sampler for determination of density, biomass, life cycle and secondary production of H. australis. For determination of C, N, P and OM in both sediment and H. australis, the samples were carried out in May and November 1999, and in April 2000. Density was significantly lower at station 1, whereas biomass did not differ significantly between the stations. Secondary production at station 1 was 28.33 g ash-free dry weight (AFDW) m -2 year -1 and at station 2 it was 49.36 g (AFDW) m -2 year -1. The concentrations of OM, C and P in the sediment and N and P in the biomass of the organisms were higher at station 2. The release of domestic effluents into this lagoon results in an increase in OM, C and P concentrations in the sediment which are reflected in H. australis chemical composition. Considering the high densities, biomass and N and P content of these snails in Imboassica lagoon, their importance for the nutrient cycling in this ecosystem must be accounted.

  3. High nutrient transport and cycling potential revealed in the microbial metagenome of Australian sea lion (Neophoca cinerea faeces.

    Directory of Open Access Journals (Sweden)

    Trish J Lavery

    Full Text Available Metagenomic analysis was used to examine the taxonomic diversity and metabolic potential of an Australian sea lion (Neophoca cinerea gut microbiome. Bacteria comprised 98% of classifiable sequences and of these matches to Firmicutes (80% were dominant, with Proteobacteria and Actinobacteria representing 8% and 2% of matches respectively. The relative proportion of Firmicutes (80% to Bacteriodetes (2% is similar to that in previous studies of obese humans and obese mice, suggesting the gut microbiome may confer a predisposition towards the excess body fat that is needed for thermoregulation within the cold oceanic habitats foraged by Australian sea lions. Core metabolic functions, including carbohydrate utilisation (14%, protein metabolism (9% and DNA metabolism (7% dominated the metagenome, but in comparison to human and fish gut microbiomes there was a significantly higher proportion of genes involved in phosphorus metabolism (2.4% and iron scavenging mechanisms (1%. When sea lions defecate at sea, the relatively high nutrient metabolism potential of bacteria in their faeces may accelerate the dissolution of nutrients from faecal particles, enhancing their persistence in the euphotic zone where they are available to stimulate marine production.

  4. The links between global carbon, water and nutrient cycles in an urbanizing world — the case of coastal eutrophication

    NARCIS (Netherlands)

    Kroeze, C.; Hofstra, N.; Ivens, W.; Löhr, A.; Strokal, M.; Wijnen, van J.

    2013-01-01

    The natural cycles of carbon (C), nitrogen (N), phosphorus (P) and water have been disturbed substantially by human activities. Urbanizing coastal drainage basins and large river deltas are located at the interface of freshwater and coastal components of the larger earth system and the process of

  5. Nutrient cycling potential of camelina (Camelina sativa L. Crantz.) as a cover crop in the US Northern Great Plains

    Science.gov (United States)

    Berti, Marisol; Samarappuli, Dulan

    2017-04-01

    Camelina [Camelina sativa (L.) Crantz.] is an industrial oilseed crop in the Brassicaceae family with multiple uses. Currently, camelina is not used as a cover crop, but it has the potential to be used as such in maize-soybean-wheat cropping systems. The objectives of this study were to determine the agronomic performance and nutrient scavenging potential of winter camelina in comparison with other common cover crops. Experiments were conducted in Fargo, ND in 2015 and 2016, and in Prosper, ND in 2015. The experimental design was a randomized complete block design with a split-plot arrangement with three replicates. The main plot was the sowing date and the subplot were camelina cultivars as well as other common cover crops in the area. Sowing dates were targeted to 15 August and September 1, although the final dates varied slightly each year. Biomass yield, N content of the biomass N uptake and P uptake was evaluated. Winter camelina N and P uptake ranged between 21 and 30.5 kg N ha-1 and 3.4 to 5.3 kg P ha-1. The nutrient scavenging potential of winter camelina was similar to other cover crops although slightly lower than turnip (Brassica rapa L.), radish (Raphanus sativus L.), and rape (Brassica napus L.) cultivars which had significantly higher P uptake than winter camelina and the other cover crops in the study. An evaluation of spring regrowth and cover indicated that only rye, winter camelina, and pennycress (Thlaspi arvense L.) survived the winter, although a few plants of triticale (x Trticosecale Witt.) and rape were found on a few plots. Because of the high variability on the plots there were no significant differences among the surviving cover crops on soil coverage. The soil coverage for rye cultivars was 25 and 35% and for camelina cv. Bison was 27%.In 2016, biomass yield was not significant for sowing date, cultivars, or their interaction. Winter camelina cultivars biomass yield fluctuated between 1.15 and 2.33 Mg dry matter ha-1 on the first sowing

  6. Precambrian biota: protistan origin of trace fossils?

    Science.gov (United States)

    Pawlowski, Jan; Gooday, Andrew J

    2009-01-13

    Some Precambrian trace fossils have been presented as evidence for the early origin of bilaterians; the recent finding that large amoeboid protists leave macroscopic traces at the bottom of the deep ocean questions the metazoan nature of early trace fossils, stressing the importance of single-cell organisms in Precambrian biota.

  7. Richness, biomass, and nutrient content of a wetland macrophyte community affect soil nitrogen cycling in a diversity-ecosystem functioning experiment

    Science.gov (United States)

    Korol, Alicia R.; Ahn, Changwoo; Noe, Gregory

    2016-01-01

    The development of soil nitrogen (N) cycling in created wetlands promotes the maturation of multiple biogeochemical cycles necessary for ecosystem functioning. This development proceeds from gradual changes in soil physicochemical properties and influential characteristics of the plant community, such as competitive behavior, phenology, productivity, and nutrient composition. In the context of a 2-year diversity experiment in freshwater mesocosms (0, 1, 2, 3, or 4 richness levels), we assessed the direct and indirect impacts of three plant community characteristics – species richness, total biomass, and tissue N concentration – on three processes in the soil N cycle – soil net ammonification, net nitrification, and denitrification potentials. Species richness had a positive effect on net ammonification potential (NAP) through higher redox potentials and likely faster microbial respiration. All NAP rates were negative, however, due to immobilization and high rates of ammonium removal. Net nitrification was inhibited at higher species richness without mediation from the measured soil properties. Higher species richness also inhibited denitrification potential through increased redox potential and decreased nitrification. Both lower biomass and/or higher tissue ratios of carbon to nitrogen, characteristics indicative of the two annual plants, were shown to have stimulatory effects on all three soil N processes. The two mediating physicochemical links between the young macrophyte community and microbial N processes were soil redox potential and temperature. Our results suggest that early-successional annual plant communities play an important role in the development of ecosystem N multifunctionality in newly created wetland soils.

  8. Bacterial Active Community Cycling in Response to Solar Radiation and Their Influence on Nutrient Changes in a High-Altitude Wetland.

    Science.gov (United States)

    Molina, Verónica; Hernández, Klaudia; Dorador, Cristina; Eissler, Yoanna; Hengst, Martha; Pérez, Vilma; Harrod, Chris

    2016-01-01

    Microbial communities inhabiting high-altitude spring ecosystems are subjected to extreme changes in solar irradiance and temperature throughout the diel cycle. Here, using 16S rRNA gene tag pyrosequencing (cDNA) we determined the composition of actively transcribing bacteria from spring waters experimentally exposed through the day (morning, noon, and afternoon) to variable levels of solar radiation and light quality, and evaluated their influence on nutrient recycling. Solar irradiance, temperature, and changes in nutrient dynamics were associated with changes in the active bacterial community structure, predominantly by Cyanobacteria, Verrucomicrobia, Proteobacteria, and 35 other Phyla, including the recently described Candidate Phyla Radiation (e.g., Parcubacteria, Gracilibacteria, OP3, TM6, SR1). Diversity increased at noon, when the highest irradiances were measured (3.3-3.9 H', 1125 W m -2 ) compared to morning and afternoon (0.6-2.8 H'). This shift was associated with a decrease in the contribution to pyrolibraries by Cyanobacteria and an increase of Proteobacteria and other initially low frequently and rare bacteria phyla (solar radiation. In addition, the percentage contribution of cyanobacterial sequences in the afternoon was similar to those recorded in the morning. The shifts in the contribution by Cyanobacteria also influenced the rate of change in nitrate, nitrite, and phosphate, highlighted by a high level of nitrate accumulation during hours of high radiation and temperature associated with nitrifying bacteria activity. We did not detect ammonia or nitrite oxidizing bacteria in situ , but both functional groups ( Nitrosomona and Nitrospira ) appeared mainly in pyrolibraries generated from dark incubations. In total, our results reveal that both the structure and the diversity of the active bacteria community was extremely dynamic through the day, and showed marked shifts in composition that influenced nutrient recycling, highlighting how abiotic

  9. Life cycle assessment of different strategies for energy and nutrient recovery from source sorted organic fraction of household waste

    DEFF Research Database (Denmark)

    Khoshnevisan, Benyamin; Tsapekos, Panagiotis; Alvarado-Morales, Merlin

    2018-01-01

    This study attempted to apply life cycle assessment (LCA) methodology to compare distinctive management strategies when biologically treating source-sorted organic household waste (SSOHW). The management strategies included different pretreatment methods of SSOHW prior to anaerobic digestion...... obtained, it can be concluded that CHP production would be the best downstream management option while the results were so sensitive to the source of substituted energy....

  10. Radiation Dose Assessment Model for Marine Biota (K-BIOTA-DYN-M)

    Energy Technology Data Exchange (ETDEWEB)

    Keum, Dong-Kwon; Kim, Byeong-Ho; Jun, In; Lim, Kwang-Muk; Choi, Yong-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    In this study, a dynamic compartment model based on the food chain of marine biota, which can be used with easily obtainable ecological parameters, is presented to predict the activity concentration and dose rate of marine biota as a result of a nuclear. The model was applied to investigate a long-term effect of the Fukushima accident on the marine biota by using {sup 131}I, {sup 134}Cs, and {sup 137}Cs activity concentrations of seawater measured for up to about 2.5years after the accident in the port of FDNPS, which was known to be the most severely contaminated. A dynamic compartment model was presented to assess the activity concentration and whole body dose rate of marine biota, and was tested through the prediction of the activity concentration and dose rate of the marine biota using the seawater activities of {sup 131}I, {sup 134}Cs, and {sup 137}Cs measured after the accident at two locations in the port of the Fukushima Daiichi Nuclear Power Station (FDNPS), as a result the Fukushima nuclear accident that occurred on March 11, 2011. The prediction results showed the radiological effect on the population of the marine biota as a consequence of the accident was insignificant. This result is also valid for biota in a less contaminated offshore because the present assessment was made for the most highly contaminated area such as marine ecosystem in the port of FDNPS. Conclusively, the present dynamic model can be usefully applied to estimate the activity concentration and whole body dose rate of the marine biota as the consequence of a nuclear accident.

  11. Biotic replacement and mass extinction of the Ediacara biota.

    Science.gov (United States)

    Darroch, Simon A F; Sperling, Erik A; Boag, Thomas H; Racicot, Rachel A; Mason, Sara J; Morgan, Alex S; Tweedt, Sarah; Myrow, Paul; Johnston, David T; Erwin, Douglas H; Laflamme, Marc

    2015-09-07

    The latest Neoproterozoic extinction of the Ediacara biota has been variously attributed to catastrophic removal by perturbations to global geochemical cycles, 'biotic replacement' by Cambrian-type ecosystem engineers, and a taphonomic artefact. We perform the first critical test of the 'biotic replacement' hypothesis using combined palaeoecological and geochemical data collected from the youngest Ediacaran strata in southern Namibia. We find that, even after accounting for a variety of potential sampling and taphonomic biases, the Ediacaran assemblage preserved at Farm Swartpunt has significantly lower genus richness than older assemblages. Geochemical and sedimentological analyses confirm an oxygenated and non-restricted palaeoenvironment for fossil-bearing sediments, thus suggesting that oxygen stress and/or hypersalinity are unlikely to be responsible for the low diversity of communities preserved at Swartpunt. These combined analyses suggest depauperate communities characterized the latest Ediacaran and provide the first quantitative support for the biotic replacement model for the end of the Ediacara biota. Although more sites (especially those recording different palaeoenvironments) are undoubtedly needed, this study provides the first quantitative palaeoecological evidence to suggest that evolutionary innovation, ecosystem engineering and biological interactions may have ultimately caused the first mass extinction of complex life. © 2015 The Author(s).

  12. Nutrient-cycling microbes in coastal Douglas-fir forests: regional-scale correlation between communities, in situ climate, and other factors.

    Science.gov (United States)

    Shay, Philip-Edouard; Winder, Richard S; Trofymow, J A

    2015-01-01

    Microbes such as fungi and bacteria play fundamental roles in litter-decay and nutrient-cycling; however, their communities may respond differently than plants to climate change. The structure (diversity, richness, and evenness) and composition of microbial communities in climate transects of mature Douglas-fir stands of coastal British Columbia rainshadow forests was analyzed, in order to assess in situ variability due to different temperature and moisture regimes. We compared denaturing gradient gel electrophoresis profiles of fungi (18S-FF390/FR1), nitrogen-fixing bacteria (NifH-universal) and ammonia-oxidizing bacteria (AmoA) polymerase chain reaction amplicons in forest floor and mineral soil samples from three transects located at different latitudes, each transect spanning the Coastal Western Hemlock and Douglas-fir biogeoclimatic zones. Composition of microbial communities in both soil layers was related to degree days above 0°C (2725-3489), while pH (3.8-5.5) best explained shifts in community structure. At this spatial scale, climatic conditions were likely to directly or indirectly select for different microbial species while local site heterogeneity influenced community structure. Significant changes in microbial community composition and structure were related to differences as small as 2.47% and 2.55°C in mean annual moisture and temperature variables, respectively. The climatic variables best describing microbial composition changed from one functional group to the next; in general they did not alter community structure. Spatial distance, especially associated with latitude, was also important in accounting for community variability (4-23%); but to a lesser extent than the combined influence of climate and soil characteristics (14-25%). Results suggest that in situ climate can independently account for some patterns of microbial biogeography in coastal Douglas-fir forests. The distribution of up to 43% of nutrient-cycling microorganisms detected in

  13. Local adaptation of aboveground herbivores towards plant phenotypes induced by soil biota.

    Directory of Open Access Journals (Sweden)

    Dries Bonte

    2010-06-01

    Full Text Available Soil biota may trigger strong physiological responses in plants and consequently induce distinct phenotypes. Plant phenotype, in turn, has a strong impact on herbivore performance. Here, we tested the hypothesis that aboveground herbivores are able to adapt to plant phenotypes induced by soil biota.We bred spider mites for 15 generations on snap beans with three different belowground biotic interactions: (i no biota (to serve as control, (ii arbuscular mycorrhizal fungi and (ii root-feeding nematodes. Subsequently, we conducted a reciprocal selection experiment using these spider mites, which had been kept on the differently treated plants. Belowground treatments induced changes in plant biomass, nutrient composition and water content. No direct chemical defence through cyanogenesis was detected in any of the plant groups. Growth rates of spider mites were higher on the ecotypes on which they were bred for 15 generations, although the statistical significance disappeared for mites from the nematode treatment when corrected for all multiple comparisons.These results demonstrate that belowground biota may indeed impose selection on the aboveground insect herbivores mediated by the host plant. The observed adaptation was driven by variable quantitative changes of the different separately studied life history traits (i.e. fecundity, longevity, sex-ratio, time to maturity.

  14. Life cycle assessment of microalgae-based aviation fuel: Influence of lipid content with specific productivity and nitrogen nutrient effects.

    Science.gov (United States)

    Guo, Fang; Zhao, Jing; A, Lusi; Yang, Xiaoyi

    2016-12-01

    The aim of this work is to compare the life cycle assessments of low-N and normal culture conditions for a balance between the lipid content and specific productivity. In order to achieve the potential contribution of lipid content to the life cycle assessment, this study established relationships between lipid content (nitrogen effect) and specific productivity based on three microalgae strains including Chlorella, Isochrysis and Nannochloropsis. For microalgae-based aviation fuel, the effects of the lipid content on fossil fuel consumption and greenhouse gas (GHG) emissions are similar. The fossil fuel consumption (0.32-0.68MJ·MJ -1 MBAF) and GHG emissions (17.23-51.04gCO 2 e·MJ -1 MBAF) increase (59.70-192.22%) with the increased lipid content. The total energy input decreases (2.13-3.08MJ·MJ -1 MBAF, 14.91-27.95%) with the increased lipid content. The LCA indicators increased (0-47.10%) with the decreased nitrogen recovery efficiency (75-50%). Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Toxicities of selected substances to freshwater biota

    Energy Technology Data Exchange (ETDEWEB)

    Hohreiter, D.W.

    1980-05-01

    The amount of data available concerning the toxicity of various substances to freshwater biota is so large that it is difficult to use in a practical situation, such as environmental impact assessment. In this document, summary tables are presented showing acute and/or chronic toxicity of selected substances for various groups of aquatic biota. Each entry is referenced to its original source so that details concerning experimental conditions may be consulted. In addition, general information concerning factors modifying toxicity, synergisms, evidence of bioaccumulation, and water quality standards and criteria for the selected substances is given. The final table is a general toxicity table designed to provide an easily accessible and general indication of toxicity of selected substances in aquatic systems.

  16. Modelling impacts of atmospheric deposition, nutrient cycling and soil weathering on the sustainability of nine forest ecosystems

    DEFF Research Database (Denmark)

    Salm, C. van der; Vries, W.de; Olsson, M.

    1999-01-01

    To assess the impact of acid deposition on the long-term sustainability of nine oak, pine and spruce stands on sandy to loamy sandy parent material in Sweden, Denmark and The Netherlands, a dynamic soil acidification model (ReSAM) was applied. Two deposition scenarios For the period 1990-2090 were...... is predicted for northern Sweden as deposition levels are below critical loads. Soil chemistry at the recently replanted Swedish sites is dominated by changes in N cycling instead of by deposition. The CL scenario leads, especially after 2010, to a stronger decline in Al concentration compared with the BAU...... scenario, which is mainly caused by a reduction of the acid input. Up to 2010, a considerable acid input to the soil system is maintained as N supply is larger than the consumption of N by the trees. Despite the reduction of the deposition of S and N to critical loads, the readily available cation pools...

  17. Emissão de fluxos foliares, floração e ciclagem de nutrientes em clones de copa de Hevea pauciflora Fluxes emission of leaves, flowering and nutrient cycling in crown clones of Hevea pauciflora

    Directory of Open Access Journals (Sweden)

    Larissa Alexandra Cardoso Moraes

    2012-09-01

    Full Text Available A fenologia foliar tem sido utilizada como uma característica importante na seleção dos clones de Hevea spp., enquanto o teor de nutrientes na serapilheira é um bom indicador da ciclagem de nutrientes. O objetivo deste trabalho foi verificar o efeito da periodicidade de emissão de fluxos foliares na floração de copa de Hevea pauciflora, estado nutricional e qualidade da serapilheira. Foram avaliadas 15 plantas de 10 anos de idade dos clones de copa CNS G 112, CNS G 124 e CBA 2. Nas condições edafoclimáticas da Amazônia tropical úmida, a emissão de folhas e de floração de H. pauciflora ocorre com maior intensidade no segundo semestre (início do período chuvoso. A H. pauciflora apresenta maior acúmulo de serapilheira que a floresta primária e os teores foliares de 22,18 g kg-1 de N, 1,47 g kg-1 de P, 5,77 g kg-1 de K, 3,79 g kg-1 de Ca, 2,09 g kg-1 de Mg, 16,15 mg kg-1 de B, 6,14 mg kg-1 de Cu, 53,87 mg kg-1 de Fe, 66,20 mg kg-1 de Mn e 48,44 mg kg-1 de Zn podem ser utilizados como referência para essa espécie de seringueira.The leaf phenology has been used as an important characteristic in the selection of Hevea spp. clones, while the nutrient content in litter is a good indicator of nutrient cycling. The objective of this study was to verify the effect of frequency of emission of fluxes of leaves and flowers in crown of Hevea pauciflora, nutritional status and quality of litter. Fifteen plants of ten-year-old of each clones (CNS G 112, CNS G 124 and CBA 2 were evaluated. In tropical Amazonia edaphoclimatic conditions, the leaf emergence and flowering of H. pauciflora occurs with higher intensity in the second semester (beginning of rainy season. The H. pauciflora has higher quantity of litter than the primary forest, and the foliar concentrations of 22.18 g kg-1 of N, 1.47 g kg-1 of P, 5.77 g kg-1 of K, 3.79 g kg-1 de Ca, 2.09 g kg-1 of Mg, 16.15 mg kg-1 of B, 6.14 mg kg-1 of Cu, 53.87 mg kg-1 of Fe, 66.20 mg kg-1 of Mn e 48

  18. Can algal biotechnology bring effective solution for closing the phosphorus cycle? Use of algae for nutrient removal: Review of past trends and future perspectives in the context of nutrient recovery

    Directory of Open Access Journals (Sweden)

    Kateřina Sukačová

    2017-06-01

    Full Text Available Eutrophication of water by nutrient pollution is a global environmental issue. Biological methods for removing nutrients are environmentally friendly and sustainable. Therefore, this article summarizes main trends in the use of algae for removing nutrients from wastewater using both suspended and attached algal-based systems. A wide variety of algal species and experimental approaches has been tested to date. Researchers report that algae are able to effectively remove a variety of pollutants and nutrients. This review also discusses the potential of algal-based technology for nutrient, especially phosphorus, recovery. Despite the fact that effective nutrient removal has been demonstrated, there are still many challenges to be overcome in the development of succesfull technologies.

  19. Application of a Hybrid Forest Growth Model to Evaluate Climate Change Impacts on Productivity, Nutrient Cycling and Mortality in a Montane Forest Ecosystem.

    Science.gov (United States)

    Seely, Brad; Welham, Clive; Scoullar, Kim

    2015-01-01

    Climate change introduces considerable uncertainty in forest management planning and outcomes, potentially undermining efforts at achieving sustainable practices. Here, we describe the development and application of the FORECAST Climate model. Constructed using a hybrid simulation approach, the model includes an explicit representation of the effect of temperature and moisture availability on tree growth and survival, litter decomposition, and nutrient cycling. The model also includes a representation of the impact of increasing atmospheric CO2 on water use efficiency, but no direct CO2 fertilization effect. FORECAST Climate was evaluated for its ability to reproduce the effects of historical climate on Douglas-fir and lodgepole pine growth in a montane forest in southern British Columbia, Canada, as measured using tree ring analysis. The model was subsequently used to project the long-term impacts of alternative future climate change scenarios on forest productivity in young and established stands. There was a close association between predicted sapwood production and measured tree ring chronologies, providing confidence that model is able to predict the relative impact of annual climate variability on tree productivity. Simulations of future climate change suggest a modest increase in productivity in young stands of both species related to an increase in growing season length. In contrast, results showed a negative impact on stemwood biomass production (particularly in the case of lodgepole pine) for established stands due to increased moisture stress mortality.

  20. Application of a Hybrid Forest Growth Model to Evaluate Climate Change Impacts on Productivity, Nutrient Cycling and Mortality in a Montane Forest Ecosystem.

    Directory of Open Access Journals (Sweden)

    Brad Seely

    Full Text Available Climate change introduces considerable uncertainty in forest management planning and outcomes, potentially undermining efforts at achieving sustainable practices. Here, we describe the development and application of the FORECAST Climate model. Constructed using a hybrid simulation approach, the model includes an explicit representation of the effect of temperature and moisture availability on tree growth and survival, litter decomposition, and nutrient cycling. The model also includes a representation of the impact of increasing atmospheric CO2 on water use efficiency, but no direct CO2 fertilization effect. FORECAST Climate was evaluated for its ability to reproduce the effects of historical climate on Douglas-fir and lodgepole pine growth in a montane forest in southern British Columbia, Canada, as measured using tree ring analysis. The model was subsequently used to project the long-term impacts of alternative future climate change scenarios on forest productivity in young and established stands. There was a close association between predicted sapwood production and measured tree ring chronologies, providing confidence that model is able to predict the relative impact of annual climate variability on tree productivity. Simulations of future climate change suggest a modest increase in productivity in young stands of both species related to an increase in growing season length. In contrast, results showed a negative impact on stemwood biomass production (particularly in the case of lodgepole pine for established stands due to increased moisture stress mortality.

  1. Interactions of radionuclides with marine biota

    International Nuclear Information System (INIS)

    Small, L.F.

    1997-01-01

    Uptake of radioactivity by marine biota can occur through consumption of radioactive food or via direct incorporation from the seawater. As uptake occurs, radioactivity begins to distribute into and onto various body tissues, or ''compartments'', at different rates. A composite uptake curve therefore is curvilinear with time. Elimination can occur via various pathways, including fecal deposition, molting, and excretion of dissolved substances, and therefore a composite loss curve also is curvilinear. Uptake and elimination can occur simultaneously, and under constant conditions over a long time period a steady-state body burden will be achieved. Many factors can affect uptake and loss rates, as well as steady-state body burdens, and some major ones are discussed. Design of radioactivity experiments involving marine biota is explored, and a case study of a ''natural experiment'' involving both reactor-produced and fallout radionuclides in a coastal environment is presented to show how much nuclide introductions can be used to learn about nuclide biomagnification, trophic level relationships, and biological distribution of radioactivity in the sea. (author)

  2. Global Economics of Nutrient Cycling

    NARCIS (Netherlands)

    Janssen, B.H.; Oenema, O.

    2008-01-01

    This paper briefly discusses global human requirements of protein nitrogen (N) from crops and animals, and then estimates the need for fertilizer N as a function of N use efficiency, and the recycling of N from animal manure and sewage wastes. These estimates are based on various assumptions and

  3. Leucine Aminopeptidase, β-Glucosidase and Alkaline Phosphatase Activity Rates and Their Significance in Nutrient Cycles in Some Coastal Mediterranean Sites

    Directory of Open Access Journals (Sweden)

    Gabriella Caruso

    2010-03-01

    Full Text Available In aquatic microbial ecology, knowledge of the processes involved in the turnover of organic matter is of utmost importance to understand ecosystem functioning. Microorganisms are major players in the cycling of nutrients (nitrogen, phosphorus and carbon, thanks to their enzymatic activities (leucine aminopeptidase, LAP, alkaline phosphatase, AP, and β-glucosidase, β-GLU on organic polymers (proteins, organic phosphates and polysaccharides, respectively. Estimates of the decomposition rates of organic polymers are performed using fluorogenic compounds, whose hydrolysis rate allow us to obtain information on the “potential” metabolic activity of the prokaryotic community. This paper refers the enzyme patterns measured during recent oceanographic cruises performed in some coastal Mediterranean sites, not yet fully investigated in terms of microbial biogeochemical processes. Mean enzyme activity rates ranged from 5.24 to 5558.1 nM/h, from 12.68 to 244.73 nM/h and from 0.006 to 9.51 nM/h for LAP, AP and β-GLU, respectively. The highest LAP and AP activity rates were measured in the Gulf of Milazzo (Tyrrhenian Sea and in the Straits of Messina, in association with the lowest bacterioplankton abundance; in contrast, the lowest ones were found in the northern Adriatic Sea. β-GLU was more active in the Straits of Messina. Activity rates were analysed in relation to the main environmental variables. Along the northern Adriatic coastal side affected by the Po river, significant inverse relationships linked LAP and AP with salinity, pointing out that fluvial inputs provided organic substrates for microbial metabolism. Both in the Gulf of Manfredonia and in the Straits of Messina, LAP and AP levels were inversely related with the concentration of nitrate and inorganic phosphorus, respectively. In the Gulf of Milazzo, high cell-specific AP measured in spite of phosphorus availability suggested the role of this enzyme not only in phosphorus, but also

  4. Leucine aminopeptidase, beta-glucosidase and alkaline phosphatase activity rates and their significance in nutrient cycles in some coastal Mediterranean sites.

    Science.gov (United States)

    Caruso, Gabriella

    2010-03-29

    In aquatic microbial ecology, knowledge of the processes involved in the turnover of organic matter is of utmost importance to understand ecosystem functioning. Microorganisms are major players in the cycling of nutrients (nitrogen, phosphorus) and carbon, thanks to their enzymatic activities (leucine aminopeptidase, LAP, alkaline phosphatase, AP, and beta-glucosidase, beta-GLU) on organic polymers (proteins, organic phosphates and polysaccharides, respectively). Estimates of the decomposition rates of organic polymers are performed using fluorogenic compounds, whose hydrolysis rate allow us to obtain information on the "potential" metabolic activity of the prokaryotic community. This paper refers the enzyme patterns measured during recent oceanographic cruises performed in some coastal Mediterranean sites, not yet fully investigated in terms of microbial biogeochemical processes. Mean enzyme activity rates ranged from 5.24 to 5558.1 nM/h, from 12.68 to 244.73 nM/h and from 0.006 to 9.51 nM/h for LAP, AP and beta-GLU, respectively. The highest LAP and AP activity rates were measured in the Gulf of Milazzo (Tyrrhenian Sea) and in the Straits of Messina, in association with the lowest bacterioplankton abundance; in contrast, the lowest ones were found in the northern Adriatic Sea. beta-GLU was more active in the Straits of Messina. Activity rates were analysed in relation to the main environmental variables. Along the northern Adriatic coastal side affected by the Po river, significant inverse relationships linked LAP and AP with salinity, pointing out that fluvial inputs provided organic substrates for microbial metabolism. Both in the Gulf of Manfredonia and in the Straits of Messina, LAP and AP levels were inversely related with the concentration of nitrate and inorganic phosphorus, respectively. In the Gulf of Milazzo, high cell-specific AP measured in spite of phosphorus availability suggested the role of this enzyme not only in phosphorus, but also in carbon

  5. Leucine Aminopeptidase, β-Glucosidase and Alkaline Phosphatase Activity Rates and Their Significance in Nutrient Cycles in Some Coastal Mediterranean Sites

    Science.gov (United States)

    Caruso, Gabriella

    2010-01-01

    In aquatic microbial ecology, knowledge of the processes involved in the turnover of organic matter is of utmost importance to understand ecosystem functioning. Microorganisms are major players in the cycling of nutrients (nitrogen, phosphorus) and carbon, thanks to their enzymatic activities (leucine aminopeptidase, LAP, alkaline phosphatase, AP, and β-glucosidase, β-GLU) on organic polymers (proteins, organic phosphates and polysaccharides, respectively). Estimates of the decomposition rates of organic polymers are performed using fluorogenic compounds, whose hydrolysis rate allow us to obtain information on the “potential” metabolic activity of the prokaryotic community. This paper refers the enzyme patterns measured during recent oceanographic cruises performed in some coastal Mediterranean sites, not yet fully investigated in terms of microbial biogeochemical processes. Mean enzyme activity rates ranged from 5.24 to 5558.1 nM/h, from 12.68 to 244.73 nM/h and from 0.006 to 9.51 nM/h for LAP, AP and β-GLU, respectively. The highest LAP and AP activity rates were measured in the Gulf of Milazzo (Tyrrhenian Sea) and in the Straits of Messina, in association with the lowest bacterioplankton abundance; in contrast, the lowest ones were found in the northern Adriatic Sea. β-GLU was more active in the Straits of Messina. Activity rates were analysed in relation to the main environmental variables. Along the northern Adriatic coastal side affected by the Po river, significant inverse relationships linked LAP and AP with salinity, pointing out that fluvial inputs provided organic substrates for microbial metabolism. Both in the Gulf of Manfredonia and in the Straits of Messina, LAP and AP levels were inversely related with the concentration of nitrate and inorganic phosphorus, respectively. In the Gulf of Milazzo, high cell-specific AP measured in spite of phosphorus availability suggested the role of this enzyme not only in phosphorus, but also in carbon

  6. Decline of radionuclides in Columbia River biota

    Energy Technology Data Exchange (ETDEWEB)

    Cushing, C.E.; Watson, D.G.; Scott, A.J.; Gurtisen, J.M.

    1980-03-01

    In January 1971, the last of nine plutonium production reactors using direct discharge of once-through cooling waters into the Columbia River was closed. Sampling was initiated at three stations on the Columbia River to document the decline of the radionuclide body burdens in the biota of the Columbia River ecosystem. The data show that in a river-reservoir complex, the measurable body burden of fission-produced radionuclides decreased to essentially undetectable levels within 18 to 24 mo after cessation of discharge of once-through cooling water into the river. On the basis of data from the free-flowing station, we believe that this decrease would be even more rapid in an unimpounded river.

  7. Nutrients and clam contamination by Escherichia coli in a meso-tidal coastal lagoon: Seasonal variation in counter cycle to external sources

    International Nuclear Information System (INIS)

    Botelho, Maria João; Soares, Florbela; Matias, Domitília; Vale, Carlos

    2015-01-01

    Highlights: • Sources of nutrients and E. coli in Ria Formosa linked to tourism in summer. • Lower nutrient values and clam contamination by E. coli in summer. • Bactericide effect of temperature and solar radiation causes lower E. coli. • Higher biological consumption of nutrients in warmer periods. • Results mirror possible effects of climate changes on coastal lagoons. - Abstract: The clam Ruditapes decussatus was transplanted from a natural recruitment area of Ria Formosa to three sites, surveyed for nutrients in water and sediments. Specimens were sampled monthly for determination of Escherichia coli, condition index and gonadal index. Higher nutrient values in low tide reflect drainage, anthropogenic sources or sediment regeneration, emphasising the importance of water mixing in the entire lagoon driven by the tide. Despite the increase of effluent discharges in summer due to tourism, nutrient concentrations and E. coli in clams were lower in warmer periods. The bactericide effect of temperature and solar radiation was better defined in clams from the inlet channel site than from sites closer to urban effluents. High temperature in summer and torrential freshwater inputs to Ria Formosa may anticipate climate change scenarios for south Europe. Seasonal variation of nutrients and clam contamination may thus point to possible alterations in coastal lagoons and their ecosystem services

  8. Diagnosing oceanic nutrient deficiency

    Science.gov (United States)

    Moore, C. Mark

    2016-11-01

    The supply of a range of nutrient elements to surface waters is an important driver of oceanic production and the subsequent linked cycling of the nutrients and carbon. Relative deficiencies of different nutrients with respect to biological requirements, within both surface and internal water masses, can be both a key indicator and driver of the potential for these nutrients to become limiting for the production of new organic material in the upper ocean. The availability of high-quality, full-depth and global-scale datasets on the concentrations of a wide range of both macro- and micro-nutrients produced through the international GEOTRACES programme provides the potential for estimation of multi-element deficiencies at unprecedented scales. Resultant coherent large-scale patterns in diagnosed deficiency can be linked to the interacting physical-chemical-biological processes which drive upper ocean nutrient biogeochemistry. Calculations of ranked deficiencies across multiple elements further highlight important remaining uncertainties in the stoichiometric plasticity of nutrient ratios within oceanic microbial systems and caveats with regards to linkages to upper ocean nutrient limitation. This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

  9. Can algal biotechnology bring effective solution for closing the phosphorus cycle? Use of algae for nutrient removal – review of past trends and future perspectives in the context of nutrient recovery

    Czech Academy of Sciences Publication Activity Database

    Sukačová, Kateřina; Červený, Jan

    2017-01-01

    Roč. 7, č. 1 (2017), s. 63-72 ISSN 1805-0174 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : wastewater treatment * algae * nutrients removal * phosphorus recovery Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7)

  10. User's guide, version 1 RESRAD-BIOTA : a tool for implementing a graded approach to biota dose evaluation

    International Nuclear Information System (INIS)

    2004-01-01

    This Interagency Steering Committee on Radiation Standards (ISCORS) Technical Report provides a User's Guide for the RESRAD-BIOTA code. The RESRAD-BIOTA code is a tool for implementing a graded approach to biota dose evaluation. The RESRAD-BIOTA code was principally sponsored and developed by the U.S. Department of Energy (DOE), with support from the U.S. Environmental Protection Agency (EPA) and the U.S. Nuclear Regulatory Commission (NRC), through the informal interagency Ecological Radiological Work Group (ECORAD-WG). The work group was led by DOE and coordinated under the oversight of ISCORS. The RESRAD-BIOTA code provides a complete spectrum of biota dose evaluation capabilities, from methods for general screening, to comprehensive receptor-specific dose estimation. The code was designed to be consistent with and provide a tool for implementing the DOE ''Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota'' (DOE voluntary consensus Technical Standard DOE-STD-1153-2002), and to provide advanced analysis capabilities in a manner that will support the anticipated needs of DOE and other agencies. These advanced analysis capabilities were generally developed through a consensus-based process among the participating agency representatives of the ECORAD-WG

  11. Enhanced activities of organically bound tritium in biota samples

    Czech Academy of Sciences Publication Activity Database

    Světlík, Ivo; Fejgl, Michal; Malátová, I.; Tomášková, Lenka

    2014-01-01

    Roč. 93, NOV (2014), s. 82-86 ISSN 0969-8043 Institutional support: RVO:61389005 Keywords : NE-OBT * HTO * NPPs * combustion * biota Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 1.231, year: 2014

  12. Assimilation potential of water column biota: Mesocosm-based evaluations

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Ansari, Z.A.; Sadhasivan, A.; Naik, S.; Sawkar, K.

    -toxic. It reveals the findings of mesocosm experiments, conducted to evaluate the assimilation potential of water column biota (bacteria, phytoplankton, and zooplankton). Bulk water quantities from coastal locations, characterized by intense tourist activity, were...

  13. UPSTREAM-TO-DOWNSTREAM CHANGES IN NUTRIENT EXPORT RISK

    Science.gov (United States)

    One of the early operating principles of landscape ecology was the importance of studying the movement of energy, nutrients, and biota in the horizontal or x,y plane (Risser et al. 1984). The new focus on horizontal movement was in part based on the recognition that many ecol...

  14. Distribución de nitrógeno, fósforo y azufre en un cultivo de colza: efectos sobre el ciclado de nutrientes Distribution of nitrogen, phosphorus and sulfur in oilseed rape: effects on nutrient cycling

    Directory of Open Access Journals (Sweden)

    Gerardo Rubio

    2007-12-01

    Full Text Available Comparado con otros cultivos, la colza tiene una alta demanda de azufre (S por lo que sería esperable que la inclusión de este cultivo en la rotación agrícola acelere el agotamiento de este nutriente en los suelos de las áreas cultivadas. En este trabajo, se comparan los patrones de partición de biomasa, S, nitrógeno (N y fósforo (P en plantas maduras de colza. La información a obtener es relevante desde el punto de vista del ciclado de nutrientes. Para ello se realizó un experimento de campo que se ajustó a un arreglo factorial con dos factores (N y S. En el momento de la cosecha, se midió la acumulación de biomasa, N, P y S en tres compartimientos: granos, rastrojo (resto de parte aérea y raíces. Aunque el rendimiento fue afectado levemente por la adición individual de N o S, la simultánea adición de ambos nutrientes provocó un incremento del 56%. El N y el P presentaron una distribución semejante entre los órganos de la planta estudiados, sin embargo, el S difirió marcadamente de ambos. Su partición al órgano que se exporta (granos fue de menor magnitud que la observada para N y P. En cambio, su partición al rastrojo en pie fue mayor. Esta característica atenuaría los efectos de la alta demanda de S sobre la exportación del cultivo y permitiría una reutilización del fertilizante agregado por el cultivo siguiente.Oilseed rape poses a higher sulfur (S demand, compared to other crops. This may indicate that the inclusion of this crop in the crop rotation could accelerate soil S depletion. In this work, we compared the allocation of biomass, nitrogen (N, phosphorus (P and S in oilseed rape mature plants. Two factors were analyzed in a field experiment: nitrogen and sulphur (two levels for each factor. At harvest, we measured the accumulation of biomass, N, P and S in three compartments: roots, straw and grains. Yield was little affected by the addition of single nutrients but the simultaneous addition of N and S

  15. Radiation dose assessment for the biota of terrestrial ecosystems in the shoreline zone of the Chernobyl nuclear power plant cooling pond.

    Science.gov (United States)

    Oskolkov, Boris Ya; Bondarkov, Mikhail D; Gaschak, Sergey P; Maksimenko, Andrey M; Hinton, Thomas G; Coughlin, Daniel; Jannik, G Timothy; Farfán, Eduardo B

    2011-10-01

    Radiation exposure of the biota in the shoreline area of the Chernobyl Nuclear Power Plant Cooling Pond was assessed to evaluate radiological consequences from the decommissioning of the Cooling Pond. This paper addresses studies of radioactive contamination of the terrestrial faunal complex and radionuclide concentration ratios in bodies of small birds, small mammals, amphibians, and reptiles living in the area. The data were used to calculate doses to biota using the ERICA Tool software. Doses from 90Sr and 137Cs were calculated using the default parameters of the ERICA Tool and were shown to be consistent with biota doses calculated from the field data. However, the ERICA dose calculations for plutonium isotopes were much higher (2-5 times for small mammals and 10-14 times for birds) than the doses calculated using the experimental data. Currently, the total doses for the terrestrial biota do not exceed maximum recommended levels. However, if the Cooling Pond is allowed to draw down naturally and the contaminants of the bottom sediments are exposed and enter the biological cycle, the calculated doses to biota may exceed the maximum recommended values. The study is important in establishing the current exposure conditions such that a baseline exists from which changes can be documented following the lowering of the reservoir water. Additionally, the study provided useful radioecological data on biota concentration ratios for some species that are poorly represented in the literature.

  16. Radiation Dose Assessment For The Biota Of Terrestrial Ecosystems In The Shoreline Zone Of The Chernobyl Nuclear Power Plant Cooling Pond

    International Nuclear Information System (INIS)

    Farfan, E.; Jannik, T.

    2011-01-01

    Radiation exposure of the biota in the shoreline area of the Chernobyl Nuclear Power Plant Cooling Pond was assessed to evaluate radiological consequences from the decommissioning of the Cooling Pond. The article addresses studies of radioactive contamination of the terrestrial faunal complex and radionuclide concentration ratios in bodies of small birds, small mammals, amphibians, and reptiles living in the area. The data were used to calculate doses to biota using the ERICA Tool software. Doses from 90 Sr and 137 Cs were calculated using the default parameters of the ERICA Tool and were shown to be consistent with biota doses calculated from the field data. However, the ERICA dose calculations for plutonium isotopes were much higher (2-5 times for small mammals and 10-14 times for birds) than the doses calculated using the experimental data. Currently, the total doses for the terrestrial biota do not exceed maximum recommended levels. However, if the Cooling Pond is allowed to drawdown naturally and the contaminants of the bottom sediments are exposed and enter the biological cycle, the calculated doses to biota may exceed the maximum recommended values. The study is important in establishing the current exposure conditions such that a baseline exists from which changes can be documented following the lowering of the reservoir water. Additionally, the study provided useful radioecological data on biota concentration ratios for some species that are poorly represented in the literature.

  17. Produção de serapilheira e ciclagem de nutrientes na cultura do cajueiro anão precoce Litter production and nutrient cycles in the young dwarf cashew culture

    Directory of Open Access Journals (Sweden)

    Ismail Soares

    2008-02-01

    Full Text Available O estudo teve por objetivos: (a avaliar a produção de biomassa proveniente da copa do cajueiro-anão precoce, clone CCP 76, com idades de 2, 3, 8 e 9 anos de implantação da cultura; (b determinar a taxa de decomposição das folhas; e (c quantificar a contribuição de nutrientes potencialmente disponíveis na biomassa para serem reciclados no solo. O trabalho foi conduzido no Campo Experimental do Curu, no Município de Paraipaba, CE, no período de dezembro de 2003 a janeiro de 2005. Os tratamentos constituíam de pomares com 2, 3, 8 e 9 anos de implantação, distribuídos em delineamentos inteiramente casualizados com oito repetições. Para a coleta da serapilheira, utilizaram-se coletores de 1 m² com malha de 1 mm² colocados a 40 cm da superfície do solo. Após a coleta, o material foi separado em frações: folhas, galhos, inflorescência, pedúnculo e castanha, que após secadas em estufa foram pesadas. Na fração folhas, determinaram-se os teores de N, P, K, Ca, Mg, S, Na, Cu, Fe, Mn e Zn. De cada planta, coletaram-se folhas prestes a cair, para determinar a taxa de decomposição. Utilizaram-se 12 g desse material seco em estufa, o qual foi colocado em bolsas de náilon com 20 x 20cm e malha de 2mm, as quais foram distribuídas na superfície do solo e coletadas após 112, 233 e 369 dias. Em cada coleta, o material foi seco em estufa, determinando-se as quantidades remanescentes de biomassa e de nutrientes (N, P, K, Ca, Mg, S, Na, Cu, Fe, Mn e Zn. As plantas com 8 e 9 anos de implantação depositaram maiores quantidades de serapilheira durante o período do experimento e apresentaram os maiores potenciais de reciclagem de nutrientes. Durante o período do experimento, observou-se, de modo geral, que o processo de decomposição foi rápido nos primeiros quatro meses e, posteriormente, manteve-se lento até o término das observações. No cajueiro, a maior parte dos nutrientes foi liberada nos primeiros quatro meses de

  18. Extração de nutrientes pelos ramos frutíferos de caquizeiro cultivar giombo durante um ciclo de produção Nutrients uptake by fruitful branches of persimmon cv. giombo in one cycle of production

    Directory of Open Access Journals (Sweden)

    Hideaki Wilson Takahashi

    2010-03-01

    Full Text Available A literatura brasileira apresenta poucos dados para subsidiar a recomendação de adubação para a cultura do caquizeiro, portanto o objetivo deste trabalho foi estudar o acúmulo de massa seca e macronutrientes nos órgãos que compõem o ramo produtivo, ao longo dos estádios fenológicos da cultura de caqui cultivar Giombo e quantificar as necessidades de nutrientes para a produção. O estudo foi realizado em pomar localizado no município de Faxinal-PR, e as amostragens de ramos frutíferos foram iniciadas três semanas após o início da brotação, repetidas a cada três semanas, durante 45 semanas. Foram realizadas análises químicas dos materiais coletados e determinada a extração de nutrientes ao longo do estádio de desenvolvimento. O total de macronutrientes exportados pela colheita dos frutos foram: 25,47; 5.72; 51.53; 6.76; 2.79 e 5,09, respectivamente, para N, P, K, Ca, Mg e S em kg por ha, para produtividade de 27.7 toneladas por ha de fruto, e os exportados pela retirada de ramos podados para fora do pomar, por questões fitossanitárias, foram: 2,1; 0,3; 1,1; 5,8; 0,5 e 0,4 kg de N, P, K, Ca, Mg e S em kg por ha.There is no information supporting fertilization for persimmon crop as far as the Brazilian literature is concerned. Therefore, the goal of this paper was to study the accumulation of dry mass and micronutrient in organs that compounds the productive branch, during phenological growth stages of persimmon cv. Giombo, and to quantify the nutrient requirement for production. The study was carried out in an orchard located in Faxinal-PR. The spacing between plants was 6 x 7 meters. The sampling of fruiting branches started three weeks after budding had begun and this procedure was repeated after every three weeks during 45 weeks. Chemical analyses of the samples were performed and nutrients extractions during phenological growth stages were determinate. The total of macronutrients removed by fruit harvest was 25.47; 5

  19. Dry Matter Production, Nutrient Cycled and Removed, and Soil Fertility Changes in Yam-Based Cropping Systems with Herbaceous Legumes in the Guinea-Sudan Zone of Benin

    Directory of Open Access Journals (Sweden)

    Raphiou Maliki

    2016-01-01

    Full Text Available Traditional yam-based cropping systems (shifting cultivation, slash-and-burn, and short fallow often result in deforestation and soil nutrient depletion. The objective of this study was to determine the impact of yam-based systems with herbaceous legumes on dry matter (DM production (tubers, shoots, nutrients removed and recycled, and the soil fertility changes. We compared smallholders’ traditional systems (1-year fallow of Andropogon gayanus-yam rotation, maize-yam rotation with yam-based systems integrated herbaceous legumes (Aeschynomene histrix/maize intercropping-yam rotation, Mucuna pruriens/maize intercropping-yam rotation. The experiment was conducted during the 2002 and 2004 cropping seasons with 32 farmers, eight in each site. For each of them, a randomized complete block design with four treatments and four replicates was carried out using a partial nested model with five factors: Year, Replicate, Farmer, Site, and Treatment. Analysis of variance (ANOVA using the general linear model (GLM procedure was applied to the dry matter (DM production (tubers, shoots, nutrient contribution to the systems, and soil properties at depths 0–10 and 10–20 cm. DM removed and recycled, total N, P, and K recycled or removed, and soil chemical properties (SOM, N, P, K, and pH water were significantly improved on yam-based systems with legumes in comparison with traditional systems.

  20. Teores e acúmulo de nutrientes durante o ciclo da mandioquinha-salsa em função da aplicação de nitrogênio, fósforo e potássio Levels and accumulation of nutrients in the cycle of peruvian carrot with application of nitrogen, phosphorus and potassium

    Directory of Open Access Journals (Sweden)

    Adriano Portz

    2006-09-01

    Full Text Available Apesar da cultura da mandioquinha-salsa (Arracacia xanthorrhiza Bancroft ser cultivada há bastante tempo no País, informações referentes aos seus aspectos nutricionais e seu desenvolvimento no campo são ainda incipientes. O estudo dos teores de nutrientes e seu comportamento ao longo do ciclo ontogenético é importante para se estabelecer uma correta recomendação de fertilizantes, níveis críticos e conseqüentemente uma maior produção de raízes comerciais. Com o objetivo de avaliar os teores e o acúmulo de macro e micronutrientes na cultura durante seu desenvolvimento, foi realizado um experimento de campo com três níveis de N, P e K, na região de Nova Friburgo-RJ, utilizando um delineamento experimental de blocos ao acaso com quatro repetições. Foram realizadas quatro amostragens ao longo do ciclo da cultura e coletadas três partes da planta (folhas, propágulo e raízes, observando-se ao longo do tempo o comportamento dos teores e o acúmulo dos nutrientes nessas partes. Não foi observada correlação dos teores de nutrientes nas partes da planta, nas épocas de amostragem, com a produção de raízes comerciais. Maior acúmulo de nutrientes foi observado entre os 150 e 210 DAT nas folhas, aos 210 DAT nos propágulos e aos 300 DAT nas raízes. Os teores foram influenciados pelos tratamentos aplicados no plantio do experimento, mas não foi observada resposta no aumento de produção de raízes comerciais.The arracacha (Arracacia xanthorrhiza Bancroft culture, in spite of already being cultivated for a long time in Brazil, has still low information on its nutritional aspect, and the field development. The study of the nutrient distribution inside the plant and their behavior along the vegetative cycle is important to establish a correct fertilizer recommendation, and to provide nutritional information, besides to obtain best commercial root production. The macro and micro nutrient levels and accumulation in the crop were

  1. The soil N cycle: new insights and key challenges

    Science.gov (United States)

    van Groenigen, J. W.; Huygens, D.; Boeckx, P.; Kuyper, Th. W.; Lubbers, I. M.; Rütting, T.; Groffman, P. M.

    2015-03-01

    The study of soil N cycling processes has been, is, and will be at the centre of attention in soil science research. The importance of N as a nutrient for all biota; the ever-increasing rates of its anthropogenic input in terrestrial (agro)ecosystems; its resultant losses to the environment; and the complexity of the biological, physical, and chemical factors that regulate N cycling processes all contribute to the necessity of further understanding, measuring, and altering the soil N cycle. Here, we review important insights with respect to the soil N cycle that have been made over the last decade, and present a personal view on the key challenges of future research. We identify three key challenges with respect to basic N cycling processes producing gaseous emissions: 1. quantifying the importance of nitrifier denitrification and its main controlling factors; 2. characterizing the greenhouse gas mitigation potential and microbiological basis for N2O consumption; 3. characterizing hotspots and hot moments of denitrification Furthermore, we identified a key challenge with respect to modelling: 1. disentangling gross N transformation rates using advanced 15N / 18O tracing models Finally, we propose four key challenges related to how ecological interactions control N cycling processes: 1. linking functional diversity of soil fauna to N cycling processes beyond mineralization; 2. determining the functional relationship between root traits and soil N cycling; 3. characterizing the control that different types of mycorrhizal symbioses exert on N cycling; 4. quantifying the contribution of non-symbiotic pathways to total N fixation fluxes in natural systems We postulate that addressing these challenges will constitute a comprehensive research agenda with respect to the N cycle for the next decade. Such an agenda would help us to meet future challenges on food and energy security, biodiversity conservation, water and air quality, and climate stability.

  2. Produção de serapilheira e ciclagem de nutrientes de uma floresta estacional semidecidual em zona ripária Litter production and nutrient cycling of a semideciduous mesophytic forest in a riparian zone

    Directory of Open Access Journals (Sweden)

    Ana Rosa Tundis Vital

    2004-12-01

    Full Text Available O presente trabalho foi realizado em uma zona ripária no período de outubro de 2000 a setembro de 2001, em uma parcela representativa de mata ciliar com vegetação do tipo "Floresta Estacional Semidecidual", localizada no centro-sul do Estado de São Paulo. A produção total de serapilheira foi de 10.646,0 kg.ha-1.a-1. A maior deposição de serapilheira e nutrientes ocorreu no fim da estação seca. A transferência total de macronutrientes foi de 217,76 kg.ha-1 de N, 11,55 kg.ha-1 de P, 52,79 kg.ha-1 de K, 199,80 kg.ha-1 de Ca e 38,70 kg.ha-1 de Mg. A serapilheira acumulada foi estimada em 6.227,25 kg.ha-1, a estimativa da taxa instantânea de decomposição (K, de 1,71; e o tempo necessário para o desaparecimento de 50 e 95% da serapilheira produzida, 150 e 639 dias, respectivamente.This work was carried out in a riparian zone from October 2000 to September 2001, within a representative plot of a riparian forest with semideciduous mesophytic forest vegetation, located in the center southern region of São Paulo state. The total litter production was 10.646 kg.ha-1.y-1. The season of highest litter and nutrient deposition was the late dry season. The total macronutrient transfer was 217.76 kg.ha-1 N; 11.55 kg.ha-1 P; 52.79 kg.ha-1 K; 199.80 kg.ha-1 Ca and 38.70 kg.ha-1 Mg. The accumulated litter was estimated as 6.227 kg.ha-1, instantaneous decomposition rate (K 1.71 and time needed time for 50% and 95% litter disappearance was 150 and 639 days, respectively.

  3. The climate change for Jehol Biota and its revolution in early Cretaceous in Western Liaoning, China

    Science.gov (United States)

    Wang, M.; Weijers, J.; Wang, C.; 973 Project; Igcp555

    2010-12-01

    Jehol Biota is known by us as the biological assemblage of eosestheria, Ephemeropsis trisetalis and Lycoptera at the beginning. And then we found more fossils at near time such as Sinosauropteryx, Confuciusornis, Cathayornis, Callobatrachus sanyanensis, Archaefructaceae and other fossils in Western Liaoning, China. With the finding of those fossils, we become to think about what is the environment of this area in that time, what led to the development of such livings? In early Cretaceous, there are a lot of basins in North of Liaoning which were with plain layer in side, a lot of Lakes and volcano campaign frequently. We built up a section located in Sihetun of Liaoning with the layer is volcano-lake face. Date of the bottom is Aptian period. From TEX86 dates, we can know that the Paleatemperature is from? (the samples from the bottom is on testing and will be known soon, ), 17°C (Lake surface temperature, in the middle layer), and then 22°C(Lake surface temperature, on the top of the layer). The climate was changed from the seasonal arid or semi-arid into a warm and humid climate. With his kind of changing of the environment, the lives of Jehol Biota can survive, evolve and multiple in those basins. The movement of the volcano took the nutrients from the earth which made a flourishing many plants and plankton. This is the power of the evolution of plants. The early angiosperm came out in this time in this area which is called as Archaefructaceae. In the same time, the direction-sense, mass death of the birds and the macrofaunas showed that the exploration of the volcanoes made a lot of animals die and then be covered very quickly. In such an area where death and living was fast, there must be a quickly evolution. And it led to the formation and preservation of a large number of fossils. we found the same fossils out of the basin but later on date which showed the climate transferred to hot and dry later, and the livings in the basin were strong enough so that

  4. Enhanced activities of organically bound tritium in biota samples.

    Science.gov (United States)

    Svetlik, I; Fejgl, M; Malátová, I; Tomaskova, L

    2014-11-01

    A pilot study aimed on possible occurrence of elevated activity of non-exchangable organically bound tritium (NE-OBT) in biota was performed. The first results showed a significant surplus of NE-OBT activity in biota of the valley of Mohelno reservoir and Jihlava river. The liquid releases of HTO from the nuclear power plant Dukovany is the source of tritium in this area. This area can be a source of various types of natural samples for future studies of tritium pathways. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. What are the toxicological effects of mercury in Arctic biota?

    DEFF Research Database (Denmark)

    Dietz, Rune; Sonne, Christian; Basu, Niladri

    2013-01-01

    This review critically evaluates the available mercury (Hg) data in Arctic marine biota and the Inuit population against toxicity threshold values. In particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological...... to be one of the most vulnerable groups, with high concentrations of mercury recorded in brain tissue with associated signs of neurochemical effects. Evidence of increasing concentrations in mercury in some biota in Arctic Canada and Greenland is therefore a concern with respect to ecosystem health....

  6. Dual RNA-seq transcriptional analysis of wheat roots colonized by Azospirillum brasilense reveals up-regulation of nutrient acquisition and cell cycle genes.

    Science.gov (United States)

    Camilios-Neto, Doumit; Bonato, Paloma; Wassem, Roseli; Tadra-Sfeir, Michelle Z; Brusamarello-Santos, Liziane C C; Valdameri, Glaucio; Donatti, Lucélia; Faoro, Helisson; Weiss, Vinicius A; Chubatsu, Leda S; Pedrosa, Fábio O; Souza, Emanuel M

    2014-05-16

    The rapid growth of the world's population demands an increase in food production that no longer can be reached by increasing amounts of nitrogenous fertilizers. Plant growth promoting bacteria (PGPB) might be an alternative to increase nitrogenous use efficiency (NUE) in important crops such wheat. Azospirillum brasilense is one of the most promising PGPB and wheat roots colonized by A. brasilense is a good model to investigate the molecular basis of plant-PGPB interaction including improvement in plant-NUE promoted by PGPB. We performed a dual RNA-Seq transcriptional profiling of wheat roots colonized by A. brasilense strain FP2. cDNA libraries from biological replicates of colonized and non-inoculated wheat roots were sequenced and mapped to wheat and A. brasilense reference sequences. The unmapped reads were assembled de novo. Overall, we identified 23,215 wheat expressed ESTs and 702 A. brasilense expressed transcripts. Bacterial colonization caused changes in the expression of 776 wheat ESTs belonging to various functional categories, ranging from transport activity to biological regulation as well as defense mechanism, production of phytohormones and phytochemicals. In addition, genes encoding proteins related to bacterial chemotaxi, biofilm formation and nitrogen fixation were highly expressed in the sub-set of A. brasilense expressed genes. PGPB colonization enhanced the expression of plant genes related to nutrient up-take, nitrogen assimilation, DNA replication and regulation of cell division, which is consistent with a higher proportion of colonized root cells in the S-phase. Our data support the use of PGPB as an alternative to improve nutrient acquisition in important crops such as wheat, enhancing plant productivity and sustainability.

  7. Burgess shale-type biotas were not entirely burrowed away

    DEFF Research Database (Denmark)

    Gaines, Robert R.; Droser, Mary L.; Orr, Patrick J.

    2012-01-01

    Burgess Shale-type biotas occur globally in the Cambrian record and offer unparalleled insight into the Cambrian explosion, the initial Phanerozoic radiation of the Metazoa. Deposits bearing exceptionally preserved soft-bodied fossils are unusually common in Cambrian strata; more than 40 are now...

  8. Trace Elements Concentrations in Water and Aquatic Biota from Ase ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    www.bioline.org.br/ja. Trace Elements Concentrations in Water and Aquatic Biota from Ase Creek in Niger. Delta. OVERAH, C L; *IWEGBUE, C M A; OSSA, E K; NWAJEI, G E. Department of Chemistry, Delta State University, Abraka, Nigeria. ABSTRACT: Water, Tilapia zilli, Synodontis nigrita, Clarias angillaris, Ipomoe cearri ...

  9. Water quality impacts on instream biota of the Shingwedzi River ...

    African Journals Online (AJOL)

    Water quality impacts on instream biota of the Shingwedzi River, South Africa. PSO Fouche, W Vlok. Abstract. Water quality, macroinvertebrate diversity (using SASS5) and fish diversity (using the fish response assessment index) of the Shingwedzi River system were monitored in 2007/2008 to determine the present status ...

  10. Grassland management, soil biota and ecosystem services in sandy soils

    NARCIS (Netherlands)

    Eekeren, van N.J.M.

    2010-01-01

    Recent legislative restrictions on the use of fertilizers and irrigation, and a quest for sustainable farming systems have drawn renewed attention to the functioning of the soil and the ecosystem services it provides. Soil biota play an important role in the provision of these ecosystem services,

  11. Linking flow, water quality and potential effects on aquatic biota ...

    African Journals Online (AJOL)

    Linking the potential effects of altered water quality on aquatic biota, that may result from a change in the flow (discharge) regime, is an essential step in the maintenance of riverine ecological functioning. Determination of the environmental flow requirement of a river (as well as other activities, such as classifying the ...

  12. Above-ground biomass and nutrient accumulation in the tropical ...

    African Journals Online (AJOL)

    This means that the impact of logging in the Ebom rainforest remains low. However, additional research is needed on nutrient input in the forest from outside as well as on the impact of logging on nutrient leaching in order to get a complete picture of the nutrient cycles. Key-words: phytomass, nutrient pools, logging, ...

  13. Beyond the Fe-P-redox connection: preferential regeneration of phosphorus from organic matter as a key control on Baltic Sea nutrient cycles

    Directory of Open Access Journals (Sweden)

    T. Jilbert

    2011-06-01

    Full Text Available Patterns of regeneration and burial of phosphorus (P in the Baltic Sea are strongly dependent on redox conditions. Redox varies spatially along water depth gradients and temporally in response to the seasonal cycle and multidecadal hydrographic variability. Alongside the well-documented link between iron oxyhydroxide dissolution and release of P from Baltic Sea sediments, we show that preferential remineralization of P with respect to carbon (C and nitrogen (N during degradation of organic matter plays a key role in determining the surplus of bioavailable P in the water column. Preferential remineralization of P takes place both in the water column and upper sediments and its rate is shown to be redox-dependent, increasing as reducing conditions become more severe at greater water-depth in the deep basins. Existing Redfield-based biogeochemical models of the Baltic may therefore underestimate the imbalance between N and P availability for primary production, and hence the vulnerability of the Baltic to sustained eutrophication via the fixation of atmospheric N. However, burial of organic P is also shown to increase during multidecadal intervals of expanded hypoxia, due to higher net burial rates of organic matter around the margins of the deep basins. Such intervals may be characterized by basin-scale acceleration of all fluxes within the P cycle, including productivity, regeneration and burial, sustained by the relative accessibility of the water column P pool beneath a shallow halocline.

  14. Impacts of an invasive snail (Tarebia granifera) on nutrient cycling in tropical streams: the role of riparian deforestation in Trinidad, West Indies.

    Science.gov (United States)

    Moslemi, Jennifer M; Snider, Sunny B; Macneill, Keeley; Gilliam, James F; Flecker, Alexander S

    2012-01-01

    Non-native species and habitat degradation are two major catalysts of environmental change and often occur simultaneously. In freshwater systems, degradation of adjacent terrestrial vegetation may facilitate introduced species by altering resource availability. Here we examine how the presence of intact riparian cover influences the impact of an invasive herbivorous snail, Tarebia granifera, on nitrogen (N) cycling in aquatic systems on the island of Trinidad. We quantified snail biomass, growth, and N excretion in locations where riparian vegetation was present or removed to determine how snail demographics and excretion were related to the condition of the riparian zone. In three Neotropical streams, we measured snail biomass and N excretion in open and closed canopy habitats to generate estimates of mass- and area-specific N excretion rates. Snail biomass was 2 to 8 times greater and areal N excretion rates ranged from 3 to 9 times greater in open canopy habitats. Snails foraging in open canopy habitat also had access to more abundant food resources and exhibited greater growth and mass-specific N excretion rates. Estimates of ecosystem N demand indicated that snail N excretion in fully closed, partially closed, and open canopy habitats supplied 2%, 11%, and 16% of integrated ecosystem N demand, respectively. We conclude that human-mediated riparian canopy loss can generate hotspots of snail biomass, growth, and N excretion along tropical stream networks, altering the impacts of an invasive snail on the biogeochemical cycling of N.

  15. Impacts of an invasive snail (Tarebia granifera on nutrient cycling in tropical streams: the role of riparian deforestation in Trinidad, West Indies.

    Directory of Open Access Journals (Sweden)

    Jennifer M Moslemi

    Full Text Available Non-native species and habitat degradation are two major catalysts of environmental change and often occur simultaneously. In freshwater systems, degradation of adjacent terrestrial vegetation may facilitate introduced species by altering resource availability. Here we examine how the presence of intact riparian cover influences the impact of an invasive herbivorous snail, Tarebia granifera, on nitrogen (N cycling in aquatic systems on the island of Trinidad. We quantified snail biomass, growth, and N excretion in locations where riparian vegetation was present or removed to determine how snail demographics and excretion were related to the condition of the riparian zone. In three Neotropical streams, we measured snail biomass and N excretion in open and closed canopy habitats to generate estimates of mass- and area-specific N excretion rates. Snail biomass was 2 to 8 times greater and areal N excretion rates ranged from 3 to 9 times greater in open canopy habitats. Snails foraging in open canopy habitat also had access to more abundant food resources and exhibited greater growth and mass-specific N excretion rates. Estimates of ecosystem N demand indicated that snail N excretion in fully closed, partially closed, and open canopy habitats supplied 2%, 11%, and 16% of integrated ecosystem N demand, respectively. We conclude that human-mediated riparian canopy loss can generate hotspots of snail biomass, growth, and N excretion along tropical stream networks, altering the impacts of an invasive snail on the biogeochemical cycling of N.

  16. Nitrogen isotopic composition of organic matter from a 168 year-old coral skeleton: Implications for coastal nutrient cycling in the Great Barrier Reef Lagoon

    Science.gov (United States)

    Erler, Dirk V.; Wang, Xingchen T.; Sigman, Daniel M.; Scheffers, Sander R.; Martínez-García, Alfredo; Haug, Gerald H.

    2016-01-01

    Ongoing human activities are known to affect nitrogen cycling on coral reefs, but the full history of anthropogenic impact is unclear due to a lack of continuous records. We have used the nitrogen isotopic composition of skeleton-bound organic matter (CS-δ15N) in a coastal Porites coral from Magnetic Island in the Great Barrier Reef as a proxy for N cycle changes over a 168 yr period (1820-1987 AD). The Magnetic Island inshore reef environment is considered to be relatively degraded by terrestrial runoff; given prior CS-δ15N studies from other regions, there was an expectation of both secular change and oscillations in CS-δ15N since European settlement of the mainland in the mid 1800s. Surprisingly, CS-δ15N varied by less than 1.5‰ despite significant land use change on the adjacent mainland over the 168-yr measurement period. After 1930, CS-δ15N may have responded to changes in local river runoff, but the effect was weak. We propose that natural buffering against riverine nitrogen load in this region between 1820 and 1987 is responsible for the observed stability in CS-δ15N. In addition to coral derived skeletal δ15N, we also report, for the first time, δ15N measurements of non-coral derived organic N occluded within the coral skeleton, which appear to record significant changes in the nature of terrestrial N inputs. In the context of previous CS-δ15N records, most of which yield CS-δ15N changes of at least 5‰, the Magnetic Island coral suggests that the inherent down-core variability of the CS-δ15N proxy is less than 2‰ for Porites.

  17. Effects of nutrient enrichment on mangrove leaf litter decomposition

    NARCIS (Netherlands)

    Keuskamp, Joost A; Hefting, Mariet M; Dingemans, Bas J J; Verhoeven, Jos T A; Feller, Ilka C

    2015-01-01

    Nutrient enrichment of mangroves, a common phenomenon along densely populated coastlines, may negatively affect mangrove ecosystems by modifying internal carbon and nutrient cycling. The decomposition of litter exerts a strong influence on these processes and is potentially modified by

  18. What are the toxicological effects of mercury in Arctic biota?

    Science.gov (United States)

    Dietz, Rune; Sonne, Christian; Basu, Niladri; Braune, Birgit; O'Hara, Todd; Letcher, Robert J; Scheuhammer, Tony; Andersen, Magnus; Andreasen, Claus; Andriashek, Dennis; Asmund, Gert; Aubail, Aurore; Baagøe, Hans; Born, Erik W; Chan, Hing M; Derocher, Andrew E; Grandjean, Philippe; Knott, Katrina; Kirkegaard, Maja; Krey, Anke; Lunn, Nick; Messier, Francoise; Obbard, Marty; Olsen, Morten T; Ostertag, Sonja; Peacock, Elizabeth; Renzoni, Aristeo; Rigét, Frank F; Skaare, Janneche Utne; Stern, Gary; Stirling, Ian; Taylor, Mitch; Wiig, Øystein; Wilson, Simon; Aars, Jon

    2013-01-15

    This review critically evaluates the available mercury (Hg) data in Arctic marine biota and the Inuit population against toxicity threshold values. In particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. Species whose concentrations exceed threshold values include the polar bears (Ursus maritimus), beluga whale (Delphinapterus leucas), pilot whale (Globicephala melas), hooded seal (Cystophora cristata), a few seabird species, and landlocked Arctic char (Salvelinus alpinus). Toothed whales appear to be one of the most vulnerable groups, with high concentrations of mercury recorded in brain tissue with associated signs of neurochemical effects. Evidence of increasing concentrations in mercury in some biota in Arctic Canada and Greenland is therefore a concern with respect to ecosystem health. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. A Method for Separating PCBs and OCPs in Biota Samples

    Directory of Open Access Journals (Sweden)

    GONG Fu-qiang

    2014-10-01

    Full Text Available Chromatographic fraction and cleanup method was developed for PCBs and OCPs in biota samples, using a self-developing chro- matographic fraction instrument and solid phase mixture. The solid phase was composed of florisil(30%-35%, acid-treated silica gel(50%-60%and anhydrous sodiumsulphate(10%-15%. The recoveriesof spiked PCBsand OCPs in column ranged from 96.4% to 119% and from 78.4% to 103% respectively, while in fish fat tissue ranged from 74.4% to 100% and from 78.3% to 102% respectively. This approach was proved to be an efficient, fast, simple and cost-effective method for fraction and cleanup of PCBs and OCPs in biota samples.

  20. Associations between soil bacterial community structure and nutrient cycling functions in long-term organic farm soils following cover crop and organic fertilizer amendment.

    Science.gov (United States)

    Fernandez, Adria L; Sheaffer, Craig C; Wyse, Donald L; Staley, Christopher; Gould, Trevor J; Sadowsky, Michael J

    2016-10-01

    Agricultural management practices can produce changes in soil microbial populations whose functions are crucial to crop production and may be detectable using high-throughput sequencing of bacterial 16S rRNA. To apply sequencing-derived bacterial community structure data to on-farm decision-making will require a better understanding of the complex associations between soil microbial community structure and soil function. Here 16S rRNA sequencing was used to profile soil bacterial communities following application of cover crops and organic fertilizer treatments in certified organic field cropping systems. Amendment treatments were hairy vetch (Vicia villosa), winter rye (Secale cereale), oilseed radish (Raphanus sativus), buckwheat (Fagopyrum esculentum), beef manure, pelleted poultry manure, Sustane(®) 8-2-4, and a no-amendment control. Enzyme activities, net N mineralization, soil respiration, and soil physicochemical properties including nutrient levels, organic matter (OM) and pH were measured. Relationships between these functional and physicochemical parameters and soil bacterial community structure were assessed using multivariate methods including redundancy analysis, discriminant analysis, and Bayesian inference. Several cover crops and fertilizers affected soil functions including N-acetyl-β-d-glucosaminidase and β-glucosidase activity. Effects, however, were not consistent across locations and sampling timepoints. Correlations were observed among functional parameters and relative abundances of individual bacterial families and phyla. Bayesian analysis inferred no directional relationships between functional activities, bacterial families, and physicochemical parameters. Soil functional profiles were more strongly predicted by location than by treatment, and differences were largely explained by soil physicochemical parameters. Composition of soil bacterial communities was predictive of soil functional profiles. Differences in soil function were

  1. Biota connect aquatic habitats throughout freshwater ecosystem mosaics

    Science.gov (United States)

    Schofield, Kate A.; Alexander, Laurie C.; Ridley, Caroline E.; Vanderhoof, Melanie; Fritz, Ken M.; Autrey, Bradley; DeMeester, Julie; Kepner, William G.; Lane, Charles R.; Leibowitz, Scott; Pollard, Amina I.

    2018-01-01

    Freshwater ecosystems are linked at various spatial and temporal scales by movements of biota adapted to life in water. We review the literature on movements of aquatic organisms that connect different types of freshwater habitats, focusing on linkages from streams and wetlands to downstream waters. Here, streams, wetlands, rivers, lakes, ponds, and other freshwater habitats are viewed as dynamic freshwater ecosystem mosaics (FEMs) that collectively provide the resources needed to sustain aquatic life. Based on existing evidence, it is clear that biotic linkages throughout FEMs have important consequences for biological integrity and biodiversity. All aquatic organisms move within and among FEM components, but differ in the mode, frequency, distance, and timing of their movements. These movements allow biota to recolonize habitats, avoid inbreeding, escape stressors, locate mates, and acquire resources. Cumulatively, these individual movements connect populations within and among FEMs and contribute to local and regional diversity, resilience to disturbance, and persistence of aquatic species in the face of environmental change. Thus, the biological connections established by movement of biota among streams, wetlands, and downstream waters are critical to the ecological integrity of these systems. Future research will help advance our understanding of the movements that link FEMs and their cumulative effects on downstream waters.

  2. Impact of biological treatments of bio-waste for nutrients, energy and bio-methane recovery in a life cycle perspective.

    Science.gov (United States)

    Di Maria, Francesco; Micale, Caterina; Contini, Stefano; Morettini, Emanuela

    2016-06-01

    Composting of the source-segregated organic fraction of municipal solid waste was compared in a life cycle perspective with conventional anaerobic digestion (AD), aimed at electricity substitution, and with AD aimed at biogas upgrading into bio-methane. Three different uses of the bio-methane were considered: injection in the natural gas grid for civil heating needs; use as fuel for high efficiency co-generation; use as fuel for vehicles. Scenarios with biogas upgrading showed quite similar impact values, generally higher than those of composting and conventional AD, for which there was a lower impact. A decisive contribution to the higher impact of the scenarios with bio-methane production was by the process for biogas upgrading. In any case the substitution of natural gas with bio-methane resulted in higher avoided impacts compared to electricity substitution by conventional AD. The uncertainty analysis confirmed the positive values for eutrophication, acidification and particulate matter. Large uncertainty was determined for global warming and photochemical ozone formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Effect of sulfate fertilization on soil biota in grassland columns

    Science.gov (United States)

    Ikoyi, Israel; Donohue, John; Fowler, Andrew; Schmalenberger, Achim

    2017-04-01

    Sulfur (S) is an important macronutrient element in plant nutrition as a component of protein, enzymes, enzyme cofactors as well as being the major constituent of the amino acids cysteine and methionine. Organically bound S is the predominant form of S in the soil constituting up to 95% of S in agricultural soils. The most important form of S in terms of plant nutrition is inorganic sulfate which forms only about 5% of the total soil S content. Air pollution was the major source of S (as SO2) for plants, with up to 80% of the S obtained from this source. However, common effects of S limitation on crops such as chlorosis, yield reduction, and decrease in crop quality are becoming increasingly evident as atmospheric S supply has decreased in recent years. Recent research has shown that organically-bound S in soils is also plant-bioavailable, likely due to interconversion of organic S forms to inorganic sulfate by soil microbes. In this study, soil columns were setup in a greenhouse using moderate S (equivalent to Wisconsin S soil availability index of below 30) soils. The columns were planted with Lolium perenne and fertilized with 0 (control), 5 (low), 10 (medium) and 20 (high) kg/ha sulfate S alongside a full complement of other nutrients. Results after 14 weeks of management show a significant decrease (Pfeed data into mathematical models on biotic S cycling which serves as predictive tool for fertilizer use in agriculture.

  4. Global silica cycle paced by astronomical cycles recorded in the Mesozoic bedded chert: Implications for early Mesozoic extinctions

    Science.gov (United States)

    Ikeda, M.; Ozaki, K.; Tada, R.

    2016-12-01

    The early Mesozoic was a period of severe crisis for the world's biota and biogeochemical cycles with Permian-Triassic, Triassic-Jurassic, and Pliensbachian-Toarcian (Early Jurassic) extinctions. Here, we present an 70-Myr-long record of high-resolution biogenic silica (BSi) burial flux in the early Mesozoic deep-sea bedded chert in Japan, which record astronomical cycles of tens of thousands- to multimillion-year periodicity as the rhythmical bedding. The estimated global Bio-Si burial flux is 140% (40-500%) of that in the modern global ocean, assuming the records are representative of low-middle latitude superocean Panthalassa. This suggests that bedded chert was a major sink for dissolved silica (DSi) in the ocean, and that the BSi burial flux was proportional to the DSi input from chemical weathering over timescales longer than the oceanic residence time of DSi (periods would be explained by the increased volcanic degassing flux and enhanced organic carbon burial due to increased nutrient supply by enhanced silicate weathering, which would result in coupling of the silicate weathering and organic carbon burial. We propose the BSi burial flux reconstructed from bedded chert can be used as a semi-quantitative measure of the global chemical weathering intensity to understand the impact of volcanism on biogeochemical cycle dynamics during the mass extinction events.

  5. Managing urban nutrient biogeochemistry for sustainable urbanization.

    Science.gov (United States)

    Lin, Tao; Gibson, Valerie; Cui, Shenghui; Yu, Chang-Ping; Chen, Shaohua; Ye, Zhilong; Zhu, Yong-Guan

    2014-09-01

    Urban ecosystems are unique in the sense that human activities are the major drivers of biogeochemical processes. Along with the demographic movement into cities, nutrients flow towards the urban zone (nutrient urbanization), causing the degradation of environmental quality and ecosystem health. In this paper, we summarize the characteristics of nutrient cycling within the urban ecosystem compared to natural ecosystems. The dynamic process of nutrient urbanization is then explored taking Xiamen city, China, as an example to examine the influence of rapid urbanization on food sourced nitrogen and phosphorus metabolism. Subsequently, the concept of a nutrient footprint and calculation method is introduced from a lifecycle perspective. Finally, we propose three system approaches to mend the broken biogeochemical cycling. Our study will contribute to a holistic solution which achieves synergies between environmental quality and food security, by integrating technologies for nutrient recovery and waste reduction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Recycling nutrients in algae biorefinery

    NARCIS (Netherlands)

    Garcia Alba, Laura; Vos, M.P.; Torri, C.; Fabbri, D.; Kersten, Sascha R.A.; Brilman, Derk Willem Frederik

    2013-01-01

    Algal fuel cells: Repeated nutrient recycling is demonstrated by reusing the aqueous phase obtained from the hydrothermal liquefaction (HTL) of microalgae. This is achieved, for the first time, by performing a complete set of four continuous growth–HTL cycles. Results show similar growth rates in

  7. LITTERFALL AND NUTRIENT RETURNS IN ISOLATED STANDS ...

    African Journals Online (AJOL)

    Dr Osondu

    area has implications in returning nutrient elements to the soils of the rainforest ecosystem. Keywords: Litterfall, Nutrient returns, Seasonal variation, Southern Nigeria, Terminalia catappa, Tropical rainforest. Introduction. In the tropical rainforests, plants and soils are in equilibrium involving an almost closed cycling.

  8. Monitoring the environmental effects of CeO2 and ZnO nanoparticles through the life cycle of corn (Zea mays) plants and in situ μ-XRF mapping of nutrients in kernels.

    Science.gov (United States)

    Zhao, Lijuan; Sun, Youping; Hernandez-Viezcas, Jose A; Hong, Jie; Majumdar, Sanghamitra; Niu, Genhua; Duarte-Gardea, Maria; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2015-03-03

    Information about changes in physiological and agronomic parameters through the life cycle of plants exposed to engineered nanoparticles (NPs) is scarce. In this study, corn (Zea mays) plants were cultivated to full maturity in soil amended with either nCeO2 or nZnO at 0, 400, and 800 mg/kg. Gas exchange was monitored every 10 days, and at harvest, bioaccumulation of Ce and Zn in tissues was determined by ICP-OES/MS. The effects of NPs exposure on nutrient concentration and distribution in ears were also evaluated by ICP-OES and μ-XRF. Results showed that nCeO2 at both concentrations did not impact gas exchange in leaves at any growth stage, while nZnO at 800 mg/kg reduced net photosynthesis by 12%, stomatal conductance by 15%, and relative chlorophyll content by 10% at day 20. Yield was reduced by 38% with nCeO2 and by 49% with nZnO. Importantly, μ-XRF mapping showed that nCeO2 changed the allocation of calcium in kernels, compared to controls. In nCeO2 treated plants, Cu, K, Mn, and Zn were mainly localized at the insertion of kernels into cobs, but Ca and Fe were distributed in other parts of the kernels. Results showed that nCeO2 and nZnO reduced corn yield and altered quality of corn.

  9. Effects of land use on the water quality and biota of three streams in the Piedmont province of North Carolina

    Science.gov (United States)

    Crawford, J.K.; Lenat, D.R.

    1989-01-01

    Three small streams in North Carolina 's northern Piedmont were studied to compare the effects of land use in their watersheds on water quality characteristics and aquatic biota. Devil 's Cradle Creek (agricultural watershed) had more than two times the sediment yield of Smith Creek (forested watershed) (0.34 tons/acre compared to 0.13 tons/acre), and Marsh Creek (urban watershed) had more than four times the yield of Smith Creek (0.59 tons/acre). Concentrations of nutrients were consistently highest in Devil 's Craddle Creek. Concentrations of total copper, iron, and lead in samples from each of the three streams at times exceeded State water quality standards as did concentrations of total zinc in samples from both Smith and Marsh Creeks. Successively lower aquatic invertebrate taxa richness was found in the forested, the agricultural, and the urban watershed streams. Invertebrate biota in Smith Creek was dominated by insects, such as Ephemeroptera, that are intolerant to stress from pollution, whereas Devil 's Cradle Creek was dominated by the more tolerant Diptera, and Marsh Creek was dominated by the most pollution-tolerant group, the Oligochaeta. Fish communities in the forested and agricultural watershed streams were characterized by more species and more individuals of each species, relative to a limited community in urban Marsh Creek. Three independent variables closely linked to land use--suspended-sediment yield, suspended-sediment load, and total lead concentrations in stream water--are inversely associated with the biological communities of the streams.

  10. Assessment of metal contamination in the biota of four rivers experiencing varying degrees of human impact.

    Science.gov (United States)

    Bielmyer-Fraser, Gretchen K; Waters, Matthew Neal; Duckworth, Christina G; Patel, Pratik P; Webster, Benjamin Cole; Blocker, Amber; Crummey, Cliff Hunter; Duncan, Aundrea Nicole; Nwokike, Somuayiro Nadia; Picariello, Codie Richard; Ragan, James T; Schumacher, Erika L; Tucker, Rebecca Lea; Tuttle, Elizabeth Ann; Wiggins, Charlie Rufus

    2017-01-01

    Urbanization, agriculture, and other land transformations can affect water quality, decrease species biodiversity, and increase metal and nutrient concentrations in aquatic systems. Metal pollution, in particular, is a reported consequence of elevated anthropogenic inputs, especially from urbanized areas. The objectives of this study were to quantify metal (Cu, Al, Cd, Ni, and Pb) concentrations in the waters and biota of four streams in South Georgia, USA, and relate metal concentrations to land use and abiotic and biotic stream processes. Additionally, macrophytes, invertebrates, and fish were identified to assess biodiversity at each site. Metal concentrations in the three trophic levels differed among sites and species, correlating to differences in land use surrounding the rivers. The highest metal concentrations (except Al) were found in the streams most impacted by urbanization and development. Al concentrations were highest in streams surrounded by land dominated by forested areas. Metal content in macrophytes reflected metal concentrations in the water and was at least three orders of magnitude higher than any other trophic level. Despite metal concentration differences, all four streams contained similar water quality and were healthy based on macroinvertebrate community structure. This study provides insight into the impact of urbanization and the fate and effects of metals in river ecosystems with varying degrees of anthropogenic impact.

  11. Effects of ashes from a Brazilian savanna wildfire on water, soil and biota: An ecotoxicological approach.

    Science.gov (United States)

    Oliveira-Filho, Eduardo C; Brito, Darlan Q; Dias, Zelia M B; Guarieiro, Mayara S; Carvalho, Esther L; Fascineli, Maria L; Niva, Cintia C; Grisolia, Cesar K

    2018-03-15

    Wildfire is very common in Brazilian savannas, and its effects on water, soil and aquatic/soil organisms are poorly understood. In this study, we observed the effects of fire, especially of ashes, on surface soil and subsurface water in a typical Brazilian savanna (Cerrado sensu strictu) for one year. Soil analyses (pH, organic matter content, potential acidity, K, Ca, Mg and P) and subsurface water analyses (NO 3- , PO 4 3- Mg 2+ , Ca 2+ and K + ) were assessed. We evaluated the ecotoxicological effects of ashes on three different endpoints and species, in fish Danio rerio (embryonic development), aquatic snail Biomphalaria glabrata (reproduction) and a soil species Enchytraeus sp. (reproduction). We found a higher amount of exchangeable cations and organic matter content in short-term fire effects on soil, but the higher availability of nutrients did not affect the soil pH in field plots. The effects of ashes on soil and subsurface water did not persist for one-year post-fire, except for organic matter content in burned areas. No toxic effects were observed on hatching success and incidences of developmental abnormalities in D. rerio embryos. However, ash input had adverse effects on reproduction in snails and enchytraeids. We reported a statistically significant decrease in snail eggs exposed to the 50g.L -1 and 100g.L -1 of ashes after four weeks (pfires on soil and aquatic biota in tropical savannas. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Adubação nitrogenada na aveia preta. I - Influência na produção de matéria seca e ciclagem de nutrientes sob sistema plantio direto Black oat biomass and nutrient cycling as affected by nitrogen fertilization in soil under no-tillage

    Directory of Open Access Journals (Sweden)

    A. Santi

    2003-12-01

    % higher than in oat without N application. At the estimated N application rate of 120 kg ha-1, the amount of recycled Ca increased by 95 % and the recycled Mg by 90 %, compared to the treatment without nitrogen fertilizer. The C/N ratio of the produced residues decreased by about one unit for each 10 kg ha-1 of applied N. In conclusion, N fertilization is a viable alternative to increase the quality and quantity of black oat biomass added to soils in no-tillage systems; besides, it improves nutrient cycling.

  13. Summary of information on aquatic biota and their habitats in the Willamette Basin, Oregon, through 1995

    Science.gov (United States)

    Altman, Bob; Henson, C.M.; Waite, I.R.

    1997-01-01

    Available information on aquatic biota of the Willamette Basin was reviewed and summarized to describe current and historical conditions as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Biological parameters emphasized include the status, distribution, and trends of aquatic biota, particularly algae, macroinvertebrates, and fish; the condition of aquatic and riparian habitat in which these biota reside; and the response of these biota to natural and human-associated impacts, including the level, type, and effect of contaminants.

  14. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Stillwater Wildlife Management Area, Churchill County, Nevada, 1986-87

    International Nuclear Information System (INIS)

    Hoffman, R.J.; Hallock, R.J.; Rowe, T.G.; Lico, M.S.; Burge, H.L.

    1990-01-01

    An investigation was initiated to determine whether irrigation drainage in and near the Stillwater Wildlife Management Area has caused or has potential to cause harmful effects on human health or fish and wildlife, or may adversely affect the suitability of water for beneficial uses. Samples of surface and groundwater, bottom sediment, and biota were collected from sites upstream and downstream from the Fallon agricultural area in the Carson Desert and were analyzed for potentially toxic trace elements, including selenium. Other analyses included radioactive substances, major dissolved constituents, and nutrients in water, and pesticide residues in bottom sediments and biota. In areas affected by irrigation drainage, concentrations of the following constituents commonly were found to exceed baseline concentrations or federal and state criteria for the protection of aquatic life or the propagation of wildlife: in water, arsenic, boron, dissolved solids, sodium, and un-ionized ammonia; in bottom sediments, arsenic, lithium, mercury, molybdenum, and selenium; and in biota, arsenic, boron, chromium, copper, mercury, selenium, and zinc. In some wetlands, selenium and mercury appear to be biomagnified whereas arsenic is bioaccumulated. Some radioactive substances were substantially higher at the downstream sites compared with upstream background sites, but the significance of this to wildlife is unknown at present. 88 refs., 32 figs., 19 tabs

  15. Qwuloolt biota - Monitoring the Qwuloolt Estuarine Levee Breach Restoration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Comprehensive planning and monitoring of abiotic (hydrology, land forms, energy and nutrients, and chemistry) and biotic (plants, fish, invertebrates, birds,...

  16. The Response of Marine Biota to OAE 1b

    Science.gov (United States)

    Herrle, J. O.

    2006-12-01

    The latest Aptian to earliest Albian is characterized by the first appearance of a distinctly modern phytoplankton community accompanied by a cold episode during a generally extreme greenhouse climate. Massive burial of organic matter caused the formation of the black shale `Niveaus' Jacob, Kilian, Paquier and Leenhardt in the Vocontian Basin (SE France). This interval is reported as the Oceanic Anoxic Event 1b (OAE1b) following the definition of Leckie et al. (2002). Lasting about four million years, OAE1b facilitates analysis of rapid climate change in a greenhouse world, and crucial for understanding climate change. During latest Aptian angiosperms and diatoms became abundant in the terrestrial and marine environments (Gersonde & Haywood 1990; Heimhofer et al. 2005). Planktic foraminifera experienced their greatest turnover rates since their first appearance, accompanied by a decrease in test size and changes of the ultrastructures of their shells (Leckie et al. 2002). Calcareous nannoplankton show a major change characterized by the influx of the boreal cool water indicator Repagulum parvidentatum into the Tethyan Realm (Herrle & Mutterlose 2003). Moreover, ammonite faunas became more cosmopolitan at the expense of Tethyan taxa during this period. Both the influx of boreal nannoplankton taxa and the trend to more cosmopolitian ammonite assemblages in the Tethyan Realm was probably favored by a long-term sea level rise accompanied by a global cooling during the late Aptian to early Albian interval. Most dramatic changes of the marine carbonate system are reflected by the stepwise decrease of nannoconids and carbonate platform drowning accompanied by a positive carbon isotope excursion which is similar to the biocalcification crisis associated with the early Aptian OAE1a (Erba 1994, Weissert et al., 1998). The massive change in the global carbon cycle is probably linked to a major change in global marine productivity from a calcareous system (nannoconids

  17. Incorporating hydrologic variability into nutrient spiraling

    Science.gov (United States)

    Doyle, Martin W.

    2005-09-01

    Nutrient spiraling describes the path of a nutrient molecule within a stream ecosystem, combining the biochemical cycling processes with the downstream driving force of stream discharge. To date, nutrient spiraling approaches have been hampered by their inability to deal with fluctuating flows, as most studies have characterized nutrient retention within only a small range of discharges near base flow. Here hydrologic variability is incorporated into nutrient spiraling theory by drawing on the fluvial geomorphic concept of effective discharge. The effective discharge for nutrient retention is proposed to be that discharge which, over long periods of time, is responsible for the greatest portion of nutrient retention. A developed analytical model predicts that the effective discharge for nutrient retention will equal the modal discharge for small streams or those with little discharge variability. As modal discharge increases or discharge variability increases, the effective discharge becomes increasingly less than the modal discharge. In addition to the effective discharge, a new metric is proposed, the functionally equivalent discharge, which is the single discharge that will reproduce the magnitude of nutrient retention generated by the full hydrologic frequency distribution when all discharge takes place at that rate. The functionally equivalent discharge was found to be the same as the modal discharge at low hydrologic variability, but increasingly different from the modal discharge at large hydrologic variability. The functionally equivalent discharge provides a simple quantitative means of incorporating hydrologic variability into long-term nutrient budgets.

  18. Agrochemical residue-biota interactions in soil and aquatic ecosystems

    International Nuclear Information System (INIS)

    1980-01-01

    Two FAO/IAEA coordinated research programmes are concerned with isotopic tracer-aided studies of agrochemical residue-biota interactions in soils and aquatic ecosystems. They currently involve 18 studies in 14 countries: Brazil, Canada, Egypt, F.R. Germany, Hungary, India, Indonesia, Iraq, Israel, Malaysia, Thailand, Turkey, USA and USSR. The aim was to develop, standardize and apply labelled substrate techniques for comparative assays of primary autotrophic and microheterotrophic production and decay, and complementary tracer techniques to determine the fate, persistence and bioconcentration of trace contaminants. Comparable data were studied concerning the current status of water bodies and likely changes due to contaminants. Soil capacity to decompose undesirable contaminants and residues, and to promote desirable transformations were studied. The techniques were also applied as a diagnostic and prognostic tool, with priority given to rice ecosystems

  19. Modes of interactions between environmental drivers and marine biota

    Directory of Open Access Journals (Sweden)

    Philip eBoyd

    2015-02-01

    Full Text Available The responses of marine biota to global ocean change is characterised by multiple environmental drivers that interact to cause non-linear changes in organismal performance. Characterising interactions is critical for us to predict whether multiple drivers will accelerate or mitigate future biological responses. There is now a large body of evidence that drivers do not act independently, a common null model, but rather have synergistic or antagonistic effects on organisms. We review the literature on interactions among environmental drivers such as ocean acidification and warming, and identify three common modes of interaction: physicochemical interactions in the seawater media outside organisms, interactions that operate on organisms directly, for example by altering physiological rates; and interactions that occur through changes in ecosystems, like predation. Interactions can also occur across these levels increasing the number of permutations for interaction, and point to a diverse range of modes of interplay. Identifying the appropriate mode will help generalise interaction types to unstudied contexts.

  20. Taiwan's industrial heavy metal pollution threatens terrestrial biota

    International Nuclear Information System (INIS)

    Hsu, M.J.; Selvaraj, K.; Agoramoorthy, G.

    2006-01-01

    The bioconcentration levels of essential (Cu, Fe, Mg, Mn, and Zn) and non-essential (As, Cd, Hg, Pb, and Sn) elements have been investigated in different terrestrial biota such as fungi, plant, earthworm, snail, crab, insect, amphibian, lizard, snake, and bat including the associated soil, to investigate the ecosystem health status in Kenting National Park, Taiwan. High bioconcentrations of Cd, Hg, and Sn in snail, earthworm, crab, lizard, snake, and bat indicated a contaminated terrestrial ecosystem. High concentrations of Cd, Hg, and Sn in plant species, effective bioaccumulation of Cd by earthworm, snail, crab and bat, as well as very high levels of Hg found in invertebrates, amphibians, and reptiles revealed a strong influence from industrial pollution on the biotic community. This study for the first time presents data on the impact of heavy metal pollution on various terrestrial organisms in Taiwan. - Metal effects occur at any terrestrial levels in Taiwan

  1. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Sujatha Srinivasan

    2008-01-01

    Full Text Available The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV. PCR methods have shown that women with BV have complex communities of vaginal bacteria that include many fastidious species, particularly from the phyla Bacteroidetes and Actinobacteria. Healthy women are mostly colonized with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners, though a variety of other bacteria may be present. The microbiology of BV is heterogeneous. The presence of Gardnerella vaginalis and Atopobium vaginae coating the vaginal epithelium in some subjects with BV suggests that biofilms may contribute to this condition.

  2. A modelling framework to assess the effect of pressures on river abiotic habitat conditions and biota

    NARCIS (Netherlands)

    Kail, Jochem; Guse, Björn; Radinger, Johannes; Schröder, Maria; Kiesel, Jens; Kleinhans, Maarten; Schuurman, Filip; Fohrer, Nicola; Hering, Daniel; Wolter, Christian

    2015-01-01

    River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a

  3. Method for the analysis of polybrominated diphenylethers in sediments and biota

    NARCIS (Netherlands)

    Boer, de J.; Allchin, C.; Law, R.; Zegers, B.; Boon, J.P.

    2001-01-01

    Three institutes worked together on the development and improvement of methods for the analysis of polybrominated diphenylethers (PBDEs) in sediments and biota. The methods developed consist of a Soxhlet, Ultra Turrax* (biota) or shake-flask extraction (sediment) using hexane (or pentane)/acetone

  4. Soil biota community structure and abundance under agricultural intensification and extensification

    NARCIS (Netherlands)

    Postma-Blaauw, M.B.; Goede, de R.G.M.; Bloem, J.; Faber, J.H.; Brussaard, L.

    2010-01-01

    Understanding the impacts of agricultural intensification and extensification on soil biota communities is useful in order to preserve and restore biological diversity in agricultural soils and enhance the role of soil biota in agroecosystem functioning. Over four consecutive years, we investigated

  5. Comparison and applicability analysis of models for estimating radiological dose rates of freshwater biota

    Science.gov (United States)

    Zhang, Xiaofeng; Yang, Zongzhen; Qin, Chunli

    2018-01-01

    A number of inter-comparisons of non-human biota radiation assessment models have been fulfilled by international researchers and organizations. This paper describes the radiological impact to reference biota in Chinese inland nuclear power plant scenario, by using RESRAD-Biota, ERICA and R&D 128. The estimation results are ranging from 6.1×10-3μGy/h to 6.17×10-2μGy/h, mainly contributed by 134Cs and 137Cs, obviously below recommended limits and thus prove the biota in reservoir can be adequately protected from effluent discharge. By comparing models characteristics and performances in exercise, we conclude the ERICA tool reveals more applicability in Chinese nuclear sites and propose several suggestions to establish native framework for non-human biota assessment.

  6. Prevailing negative soil biota effect and no evidence for local adaptation in a widespread Eurasian grass.

    Directory of Open Access Journals (Sweden)

    Viktoria Wagner

    2011-03-01

    Full Text Available Soil biota effects are increasingly accepted as an important driver of the abundance and distribution of plants. While biogeographical studies on alien invasive plant species have indicated coevolution with soil biota in their native distribution range, it is unknown whether adaptation to soil biota varies among populations within the native distribution range. The question of local adaptation between plants and their soil biota has important implications for conservation of biodiversity and may justify the use of seed material from local provenances in restoration campaigns.We studied soil biota effects in ten populations of the steppe grass Stipa capillata from two distinct regions, Europe and Asia. We tested for local adaptation at two different scales, both within (ca. 10-80 km and between (ca. 3300 km regions, using a reciprocal inoculation experiment in the greenhouse for nine months. Generally, negative soil biota effects were consistent. However, we did not find evidence for local adaptation: both within and between regions, growth of plants in their 'home soil' was not significantly larger relative to that in soil from other, more distant, populations.Our study suggests that negative soil biota effects can prevail in different parts of a plant species' range. Absence of local adaptation points to the possibility of similar rhizosphere biota composition across populations and regions, sufficient gene flow to prevent coevolution, selection in favor of plasticity, or functional redundancy among different soil biota. From the point of view of plant--soil biota interactions, our findings indicate that the current practice of using seeds exclusively from local provenances in ecosystem restoration campaigns may not be justified.

  7. Nutrient status and thermal stratification in Lake Victoria

    OpenAIRE

    Mugidde, R.; Hecky, R.E.

    2004-01-01

    Worldwide, human activity in the watershed has been found to induce lake responses at various levels, including at population and ecosystem scale. Recently, Carignan and Steedman (2000) reported on disruptions of biogeochemical cycles in temperate lakes following watershed deforestation and lor wildfire and Carignan et al., (2000 a, b) concluded that water quality and aquatic biota are strongly influenced by disturbances in the watershed. Similarly, Lake Victoria is no...

  8. Predator control of ecosystem nutrient dynamics.

    Science.gov (United States)

    Schmitz, Oswald J; Hawlena, Dror; Trussell, Geoffrey C

    2010-10-01

    Predators are predominantly valued for their ability to control prey, as indicators of high levels of biodiversity and as tourism attractions. This view, however, is incomplete because it does not acknowledge that predators may play a significant role in the delivery of critical life-support services such as ecosystem nutrient cycling. New research is beginning to show that predator effects on nutrient cycling are ubiquitous. These effects emerge from direct nutrient excretion, egestion or translocation within and across ecosystem boundaries after prey consumption, and from indirect effects mediated by predator interactions with prey. Depending on their behavioural ecology, predators can create heterogeneous or homogeneous nutrient distributions across natural landscapes. Because predator species are disproportionately vulnerable to elimination from ecosystems, we stand to lose much more from their disappearance than their simple charismatic attractiveness. 2010 Blackwell Publishing Ltd/CNRS.

  9. The BIOTA Biodiversity Observatories in Africa--a standardized framework for large-scale environmental monitoring.

    Science.gov (United States)

    Jürgens, Norbert; Schmiedel, Ute; Haarmeyer, Daniela H; Dengler, Jürgen; Finckh, Manfred; Goetze, Dethardt; Gröngröft, Alexander; Hahn, Karen; Koulibaly, Annick; Luther-Mosebach, Jona; Muche, Gerhard; Oldeland, Jens; Petersen, Andreas; Porembski, Stefan; Rutherford, Michael C; Schmidt, Marco; Sinsin, Brice; Strohbach, Ben J; Thiombiano, Adjima; Wittig, Rüdiger; Zizka, Georg

    2012-01-01

    The international, interdisciplinary biodiversity research project BIOTA AFRICA initiated a standardized biodiversity monitoring network along climatic gradients across the African continent. Due to an identified lack of adequate monitoring designs, BIOTA AFRICA developed and implemented the standardized BIOTA Biodiversity Observatories, that meet the following criteria (a) enable long-term monitoring of biodiversity, potential driving factors, and relevant indicators with adequate spatial and temporal resolution, (b) facilitate comparability of data generated within different ecosystems, (c) allow integration of many disciplines, (d) allow spatial up-scaling, and (e) be applicable within a network approach. A BIOTA Observatory encompasses an area of 1 km(2) and is subdivided into 100 1-ha plots. For meeting the needs of sampling of different organism groups, the hectare plot is again subdivided into standardized subplots, whose sizes follow a geometric series. To allow for different sampling intensities but at the same time to characterize the whole square kilometer, the number of hectare plots to be sampled depends on the requirements of the respective discipline. A hierarchical ranking of the hectare plots ensures that all disciplines monitor as many hectare plots jointly as possible. The BIOTA Observatory design assures repeated, multidisciplinary standardized inventories of biodiversity and its environmental drivers, including options for spatial up- and downscaling and different sampling intensities. BIOTA Observatories have been installed along climatic and landscape gradients in Morocco, West Africa, and southern Africa. In regions with varying land use, several BIOTA Observatories are situated close to each other to analyze management effects.

  10. Long- and short-term changes in nutrient availability following commercial sawlog harvest via cable logging

    Science.gov (United States)

    Jennifer Knoepp; Wayne Swank; Bruce L. Haines

    2014-01-01

    Soil nutrient availability often limits forest productivity and soils have considerable variation in their ability to supply nutrients. Most southern Appalachian forests are minimally managed with no fertilizer inputs or routine thinning regime. Nutrient availability is regulated by atmospheric inputs and the internal cycling of nutrients through such processes as...

  11. Metals in mangrove ecosystems and associated biota: A global perspective.

    Science.gov (United States)

    Kulkarni, Rasika; Deobagkar, Deepti; Zinjarde, Smita

    2018-05-30

    Mangrove forests prevalent along the intertidal regions of tropical and sub-tropical coastlines are inimitable and dynamic ecosystems. They protect and stabilize coastal areas from deleterious consequences of natural disasters such as hurricanes and tsunamis. Although there are reviews on ecological aspects, industrial uses of mangrove-associated microorganisms and occurrence of pollutants in a region-specific manner, there is no exclusive review detailing the incidence of metals in mangrove sediments and associated biota in these ecosystems on a global level. In this review, mangrove forests have been classified in a continent-wise manner. Most of the investigations detail the distribution of metals such as zinc, chromium, arsenic, copper, cobalt, manganese, nickel, lead and mercury although in some cases levels of vanadium, strontium, zirconium and uranium have also been studied. Seasonal, tidal, marine, riverine, and terrestrial components are seen to influence occurrence, speciation, bioavailability and fate of metals in these ecosystems. In most of the cases, associated plants and animals also accumulate metals to different extents and are of ecotoxicological relevance. Levels of metals vary in a region specific manner and there is disparity in the pollution status of different mangrove areas. Protecting these vulnerable ecosystems from metal pollutants is important from environmental safety point of view. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Footprints of climate change on Mediterranean Sea biota

    Directory of Open Access Journals (Sweden)

    Núria eMarbà

    2015-08-01

    Full Text Available The Mediterranean Sea ranks among the ocean regions warming fastest. There is evidence for impacts of climate change on marine Mediterranean organisms but a quantitative assessment is lacking. We compiled the impacts of warming reported in the literature to provide a quantitative assessment for the Mediterranean Sea. During the last three decades the summer surface temperature has increased 1.15 oC. Strong heat wave events have occurred in years 1994, 2003 and 2009. Impacts of warming are evident on growth, survival, fertility, migration and phenology of pelagic and benthic organisms, from phytoplankton to marine vegetation, invertebrates and vertebrates. Overall, 50 % of biological impacts in the Mediterranean Sea occur at summer surface temperature anomaly ≤ 4.5 ºC and at summer surface temperature of 27.5 ºC. The activation energy (geometric mean 1.58 ± 0.48 eV, the slope of the Arrhenius equation describing the temperature-dependence of biological processes, for the response of Mediterranean marine biota to warming reveals that these responses in the Mediterranean are far steepest than possibly explained by the direct effect of warming alone. The observations are biased toward the northern and western sectors of the basin, likely underestimating the impacts of warming in areas where warming is particularly intense.

  13. Footprints of climate change on Mediterranean Sea biota

    KAUST Repository

    Marbà, Núria

    2015-08-13

    The Mediterranean Sea ranks among the ocean regions warming fastest. There is evidence for impacts of climate change on marine Mediterranean organisms but a quantitative assessment is lacking. We compiled the impacts of warming reported in the literature to provide a quantitative assessment for the Mediterranean Sea. During the last three decades the summer surface temperature has increased 1.15°C. Strong heat wave events have occurred in years 1994, 2003, and 2009. Impacts of warming are evident on growth, survival, fertility, migration and phenology of pelagic and benthic organisms, from phytoplankton to marine vegetation, invertebrates and vertebrates. Overall, 50% of biological impacts in the Mediterranean Sea occur at summer surface temperature anomaly ≤ 4.5°C and at summer surface temperature of 27.5°C. The activation energy (geometric mean 1.58 ± 0.48 eV), the slope of the Arrhenius equation describing the temperature-dependence of biological processes, for the response of Mediterranean marine biota to warming reveals that these responses in the Mediterranean are far steepest than possibly explained by the direct effect of warming alone. The observations are biased toward the northern and western sectors of the basin, likely underestimating the impacts of warming in areas where warming is particularly intense.

  14. Geographical Distribution and Sources of Nutrients in Atmospheric Aerosol Over the Pacific Ocean

    Science.gov (United States)

    Uematsu, M.

    2016-12-01

    The Pacific Ocean, the world's largest (occupying about 30% of the Earth's total surface area) has several distinguishing biogeochemical features. In the western Pacific, dust particles originating from arid and semi-arid regions in Asia and Australia are transported to the north and south, respectively. Biomass burning emissions from Southeast Asia are exported to the tropical Pacific, and anthropogenic substances flowing out of Asia and Eurasia spread both regionally and globally. Over high primary productive areas such as the subarctic North Pacific, the equatorial Pacific and the Southern Ocean, biogenic gasses are released to the atmosphere and transported to other areas. These processes may affect cloud and rainfall patterns, air quality, and the radiative balance of downwind regions. The deposition of atmospheric aerosols containing iron and other essential nutrients is important for biogeochemical cycles in the oceans because this source of nutrients helps sustain primary production and affects food-web structure; these effects in turn influence the chemical properties of marine atmosphere. From an atmospheric chemistry standpoint, sea-salt aerosols produced by strong winds and marine biogenic gases emitted from highly productive waters affect the physicochemical characteristics of marine aerosols. As phytoplankton populations are patchy and atmospheric processes sporadic, the interactions between atmospheric chemical constituents and marine biota vary for different regions as well as seasonally and over longer timescales. To address these and other emerging issues, and more generally to better understand the important biogeochemical processes and interactions occurring over the open oceans, more long-term recurrent research cruises with standardized atmospheric shipboard measurements will be needed in the future.

  15. A regional high resolution model of the marine mercury cycle.

    Science.gov (United States)

    Bieser, J.; Daewel, U.; Schrum, C.

    2017-12-01

    One of the main sources for mercury intoxication is the uptake of methylmercury from sea food. However, only little is known about the dynamics of methylmercury in the marine environment and its accumulation along the food chain. To further our understanding of the pathways from anthropogenic emissions of elemental mercury to the bio-accumulation of methylmercury in fish we developed the first regional Eulerian three dimensional multi-media chemistry transport model (MECOSMO) that includes atmosphere, ocean, and ecosystem. The marine part of the model includes a complete representation of the marine ecosystem ranging from phytoplankton up to higher trophic levels, including fish. We used the MECOSMO model to reconstruct mercury concentrations in water and biota in the North- and Baltic Sea for the past 60 years. Based on our model we examined the natural short and longterm variability of the system as well as long term trends in the distribution and amount of methylmercury in water and fish. Based on our findings we show how models can be utilized to develop future measurement strategies for marine mercury. Finally, the presented modelling system can be used to project the impact of future perturbations in the system (i.e.: emission reductions, climate change, nutrient control) on the mercury accumulation in sea food. Thereby, supporting the implementation of the Minamata Convention on Mercury on a regional scale by enabling us to estimate the impact of emission reductions on the marine mercury cycle.

  16. Making sense of ocean biota: how evolution and biodiversity of land organisms differ from that of the plankton.

    Science.gov (United States)

    Smetacek, Victor

    2012-09-01

    The oceans cover 70% of the planet's surface, and their planktonic inhabitants generate about half the global primary production, thereby playing a key role in modulating planetary climate via the carbon cycle. The ocean biota have been under scientific scrutiny for well over a century, and yet our understanding of the processes driving natural selection in the pelagic environment - the open water inhabited by drifting plankton and free-swimming nekton - is still quite vague. Because of the fundamental differences in the physical environment, pelagic ecosystems function differently from the familiar terrestrial ecosystems of which we are a part. Natural selection creates biodiversity but understanding how this quality control of random mutations operates in the oceans - which traits are selected for under what circumstances and by which environmental factors, whether bottom-up or top-down - is currently a major challenge. Rapid advances in genomics are providing information, particularly in the prokaryotic realm, pertaining not only to the biodiversity inventory but also functional groups. This essay is dedicated to the poorly understood tribes of planktonic protists (unicellular eukaryotes) that feed the ocean's animals and continue to run the elemental cycles of our planet. It is an attempt at developing a conceptually coherent framework to understand the course of evolution by natural selection in the plankton and contrast it with the better-known terrestrial realm. I argue that organism interactions, in particular co-evolution between predators and prey (the arms race), play a central role in driving evolution in the pelagic realm. Understanding the evolutionary forces shaping ocean biota is a prerequisite for harnessing plankton for human purposes and also for protecting the oceanic ecosystems currently under severe stress from anthropogenic pressures.

  17. Dynamic modelling of radionuclide uptake by Fukushima coastal biota - Dynamic modelling of radionuclide uptake by marine biota: application to Fukushima assessment

    Energy Technology Data Exchange (ETDEWEB)

    Vives i Batlle, Jordi [Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium)

    2014-07-01

    Radiological assessments to non-human marine biota are usually carried out by assuming that the activity concentration in an organism is proportional to the activity concentration in an adjacent volume of water, via a concentration factor (CF). It is also assumed that radionuclides in the water are in isotopic equilibrium with the sediments via a sediment distribution coefficient (K{sub d}). These assumptions are not valid in accidental situations where the biota and the sediments react with a time delay to large variations of activity concentration in seawater. A simple dynamic model was developed to factorise the dynamics of radionuclide uptake and turnover in biota and sediments, as determined by a balance between the residence time of radionuclides in seawater/sediments and the biological half-life of elimination in the biota. The model calculates activity concentration of {sup 131}I, {sup 134}Cs, {sup 137}Cs and {sup 90}Sr in seabed sediment, fish, crustaceans, molluscs and macro-algae from surrounding activity concentrations in seawater, with which to derive internal and external dose rates. A central element of this new model is the inclusion of sediment processes in dynamic transfer modelling. The model is adapted to include depletion of radionuclides adsorbed onto suspended particulates (particle scavenging), molecular diffusion, pore water mixing and bioturbation (modelled effectively as a diffusive process) represented by a simple set of differential equations that is coupled with the biological uptake/turnover processes. In this way, the model is capable of reproducing activity concentration in sediment to give a more realistic calculation of the external dose to biota compared with the simpler approach based on CF and K{sub d} values used in previous assessments. The model is applied to the assessment of the radiological impact of the Fukushima accident on marine biota in the early phase of the accident. It is shown that previous assessment of the

  18. Nutrient contributions by benthal sludge deposits.

    Science.gov (United States)

    Bhargava, Devendra S; Shrihari, S

    2009-10-01

    Settled solids from effluents discharged into a river system, undergoing decomposition at the river bottom, form an appreciable internal nutrient source for the biological activities in the river system. During the stabilization of benthal deposits, a variety of nutrients are released into the overlying waters. The exchange between sediment and overlying waters is a major component of the nitrogen and phosphorous cycles in the natural waters. The releases of such nutrients is a surface phenomenon, regulated by the conditions of benthal sludge layers, flow rate of overlying waters, etc. The rate of ammonia nitrogen release manifested an optimum low value when benthal sludge depth was 0.2 m, but was not influenced by the flow rate of overlying water and h/d ratios. The rate of phosphate release from benthal sludge was independent of depth of benthal sludge, flow rate and h/d ratios. The nutrients in the benthal sludge layers were increasing with time, and were concentrated at a layer 10 cm below the top surface. The nutrients release (percent of nutrient remaining in top benthal sludge layers) decreased with time and became almost constant after about 40 days. The nutrients release under continuously accumulating conditions of benthal sludge and the effects of frequency of addition have been discussed in this paper. The nutrients release was less when the frequency of addition was less.

  19. Crop yield, root growth, and nutrient dynamics in a conventional and three organic cropping systems with different levels of external inputs and N re-cycling through fertility building crops

    DEFF Research Database (Denmark)

    Thorup-Kristensen, Kristian; Dresbøll, Dorte Bodin; Kristensen, Hanne Lakkenborg

    2012-01-01

    of the organic rotation, both relying on green manures and catch crops grown during the autumn after the main crop as their main source of soil fertility, and the O3 system further leaving rows of the green manures to grow as intercrops between vegetable rows to improve the conditions for biodiversity...... calculated based on total land area was only 63% of conventional yields. Differences in quality parameters of the harvested crops, i.e. nutrient content, dry matter content or damages by pests or diseases were few and not systematic, whereas clear effects on nutrient balances and nitrogen leaching indicators...

  20. Are metals of antifouling paints transferred to marine biota?

    Directory of Open Access Journals (Sweden)

    Wladimir C. Paradas

    2007-03-01

    Full Text Available Because of its high toxicity, TBT (trybutiltin was banned since 2003, which resulted in a greater re-use of Cu as based-biocide in antifouling paints (AFP. The aim of this work is to determine if metals form of AFP are transferred to benthic organisms from Guanabara Bay (GB (Rio de Janeiro, Brazil. Metal concentrations were measured in two main fouling algae species Ulva flexuosa and U. fasciata and one isopod species, Sphaeroma serratum, in two GB marinas areas from sites with artificial substrate covered by AFP and natural substrate.In addition, control samples were collected in an adjacent open ocean area. Concentrations of Cd, Cr, Cu, Pb and Zn were determined by Atomic Absortion Spectrophotometry. Higher concentrations of Cu, Pb and Zn were detected in both algal species from GB in relation to control areas. Among samples of algae and isopod species from GB, populations collected over artificial surfaces covered by AFP presented significantly higher metal concentration than population of rocky natural substrate. Our data showed that the leaching of metals by antifouling paints present on decks and boats are being taken up by algae and isopods. These results indicate that antifouling coatings are the main source of heavy metal to biota of GB marina area.Devido sua alta toxicidade, o TBT está banido desde 2003, o que resultou na re-utilização de tintas a base de cobre. O objetivo deste trabalho é determinar se os metais provenientes das tintas anti-incrustantes (AFP são transferidos para organismos bentônicos da Baía de Guanabara (BG (Rio de janeiro, Brasil. Concentrações de metais foram analisadas em duas espécies de algas Ulva flexuosa e U. fasciata e no isópoda, Sphaeroma serratum, em duas áreas de marinas em locais de substrato artificial coberto com tintas AFP e em locais de substrato natural. Também foram coletadas amostras em uma área oceânica (controle. Concentrações de Cd, Cr, Cu, Pb e Zn foram determinadas por

  1. Molecular fossils from organically preserved Ediacara biota reveal cyanobacterial origin for Beltanelliformis.

    Science.gov (United States)

    Bobrovskiy, Ilya; Hope, Janet M; Krasnova, Anna; Ivantsov, Andrey; Brocks, Jochen J

    2018-03-01

    The Ediacara biota (~575-541 million years ago) mark the emergence of large, complex organisms in the palaeontological record, preluding the radiation of modern animal phyla. However, their phylogenetic relationships, even at the domain level, remain controversial. We report the discovery of molecular fossils from organically preserved specimens of Beltanelliformis, demonstrating that they represent large spherical colonies of cyanobacteria. The conservation of molecular remains in organically preserved Ediacaran organisms opens a new path for unravelling the natures of the Ediacara biota.

  2. The ecology of scattering layer biota around Indian Ocean seamounts and islands

    OpenAIRE

    Boersch-Supan, Philipp Hanno

    2014-01-01

    The waters of the open ocean constitute the largest living space on Earth but despite its obvious significance to the biosphere, the open ocean remains an unexplored frontier. With a regional focus on the Indian Ocean, this thesis investigates (i) the distribution of pelagic biota on basin scales, (ii) the effect of abrupt topography on pelagic biota and their predator-prey relationships, and (iii) the use of genetic techniques to elucidate population connectivity and dispersal of pelag...

  3. Marine biota sightings during 3D marine seismic surveys

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Joao Luiz Martinez de; Uller, George A. [CGG do Brasil, Rio de Janeiro, RJ (Brazil); Derntl, Jose Renato; Ribeiro, Camila Castroviejo da Silva; Pereira, Edisio [GEOCOOP Cooperativa de Trabalho, Rio de Janeiro, RJ (Brazil); Miranda, Cristina Maschio de [Nautilus Cooperativa de Trabalho (Brazil); Ferraz, Alexandre Almeida; Costa, Leandro Damiao Soares da [Okeanos Consultoria e Meio Ambiente Ltda. (Brazil)

    2004-07-01

    This work intends to make a correlation between the presence of the marine biota and the seismic source activity (air guns) during seismic surveys, in Campos (BM-C-25 and BM-C-16) and Santos (BM-S-3) Basin, since July 2003 until March 2004. Environmental data were acquired onboard of the Seismic Vessel CGG Harmattan by a team of four oceanographers (environmental technicians), working on the highest place of the Vessel to record and identify the animals whenever was possible. The data were recorded in forms where fields about the biotic and environmental aspects were filled. In 212 days of observations, 2580,1 hours of sighting's effort were recorded; the air guns worked during 37,6% of the time of the effort. These efforts were made during the daylight reaching an average value of 11,35 hours/day. Sightings were divided into the suborders Odontocetes and Mysticetes, and others (fishes, turtles and non identified mammals). 175 sightings were recorded, being 54% when the air gun was off (24% Mysticetes, 56% Odontocetes, 20% others). Similarly, when the air gun was working, 46% of the records were made (24% Mysticetes, 61% Odontocetes, 6% others); the major concentration (58%) of individuals was inside the 1000 m radius around the ship, followed by 14% of the individuals occurring between 3001-4000 m radius away from the ship. The analysis of the data suggests a non-evasive behavior related to the working of the seismic source, corroborating the results reached by other publications using the data collected onboard CGG Vessels. (author)

  4. Natural radioactivity in some specimens of the marine biota

    International Nuclear Information System (INIS)

    Valle Matta, M.A. do

    1980-01-01

    Marine environment contamination by natural radionuclides (uranium and 238 U daughters) is evaluated using marine -fauna and flora elements concentrating fission - and radioactivated products released by nuclear facilities. Total alpha and beta radiometry is done in the the biota to determine the radionuclide concentration. Uranium, 226 Ra and 210 PO assay is done to estimate their contribution to natural radioactivity in the chosen biological indicators. Several analytical techniques required by each radionuclide are used. Potassium assay is done to evaluate the contribution of 40 K to the natural radioactivity, and calcium assay to determine Ra/Ca and U/Ca ratios in the samples. For total alpha radiometry in algae the higher average value is detected in Phaeophyta (84.1 pCi/kg fresh weight); maximum concentration in animals is registered in Bunodosoma caissarum (43.1 pCi/kg fresh weight). For algae, the higher average total beta radiometry detected is in Chlorophyta (6.9 nCi/kg fresh weight); the maximum value found in animals refers to Thais Haemastoma (7.54 nCi/kg fresh weight). Potassium higher average ratio for algae occurs in Chlorophyta (12.77% ashes); for animals, the maximum value is found in Bunodosoma caissarum (13.80% ashes). The uranium concentration factor is maximum in Perna perna bissus (684) while the minimum is registered in Thais haemastoma and Sargassum vulgare (44). The 226 Ra concentration factor is maximum in Sargassum vulgare (2143) and minimum in Bunodosoma caissarum (32). Maximum average ratio for 210 PO in algae occurs in Phaephyta (11.5 pCi/g dry weight) and the maximum concentration for animals in Perna perna (31.5 pCi/g dry weight). The techniques employed proved to be efficient for the objectives aimed at. (Author) [pt

  5. Glyphosate and aminomethylphosphonic acid chronic risk assessment for soil biota.

    Science.gov (United States)

    von Mérey, Georg; Manson, Philip S; Mehrsheikh, Akbar; Sutton, Peter; Levine, Steven L

    2016-11-01

    Glyphosate is a broad-spectrum herbicide used widely in agriculture, horticulture, private gardens, and public infrastructure, where it is applied to areas such as roadsides, railway tracks, and parks to control the growth of weeds. The exposure risk from glyphosate and the primary soil metabolite aminomethylphosphonic acid (AMPA) on representative species of earthworms, springtails, and predatory soil mites and the effects on nitrogen-transformation processes by soil microorganisms were assessed under laboratory conditions based on internationally recognized guidelines. For earthworms, the reproductive no-observed-effect concentration (NOEC) was 472.8 mg glyphosate acid equivalent (a.e.)/kg dry soil, which was the highest concentration tested, and 198.1 mg/kg dry soil for AMPA. For predatory mites, the reproductive NOEC was 472.8 mg a.e./kg dry soil for glyphosate and 320 mg/kg dry soil for AMPA, the highest concentrations tested. For springtails, the reproductive NOEC was 472.8 mg a.e./kg dry soil for glyphosate and 315 mg/kg dry soil for AMPA, the highest concentrations tested. Soil nitrogen-transformation processes were unaffected by glyphosate and AMPA at 33.1 mg a.e./kg soil and 160 mg/kg soil, respectively. Comparison of these endpoints with worst-case soil concentrations expected for glyphosate (6.62 mg a.e./kg dry soil) and AMPA (6.18 mg/kg dry soil) for annual applications at the highest annual rate of 4.32 kg a.e./ha indicate very low likelihood of adverse effects on soil biota. Environ Toxicol Chem 2016;35:2742-2752. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

  6. Soluble organic nutrient fluxes

    Science.gov (United States)

    Robert G. Qualls; Bruce L. Haines; Wayne Swank

    2014-01-01

    Our objectives in this study were (i) compare fluxes of the dissolved organic nutrients dissolved organic carbon (DOC), DON, and dissolved organic phosphorus (DOP) in a clearcut area and an adjacent mature reference area. (ii) determine whether concentrations of dissolved organic nutrients or inorganic nutrients were greater in clearcut areas than in reference areas,...

  7. Plant nutrient capacity of vineyard soils at Grimalda area of central Istria

    OpenAIRE

    Matković, D.; Gluhič, David

    2016-01-01

    During annual grow cycle the vines develop forms of vegetative and generative organs. For this it needs plant nutrients in the soil, which are located in the root zone. Plant nutrients are substances which are necessary for the life cycle of the plant. Each nutrient element has its own specific physiological role in plant metabolism. With the highly complex functions of roots, vines take mineral nutrients from the soil, which are dissolved in water. For the successful cultivation of vines is ...

  8. Energy flow and mineral cycling mechanisms

    International Nuclear Information System (INIS)

    Rogers, L.E.

    1977-01-01

    Analysis of energy flow patterns and mineral cycling mechanisms provides a first step in identifying major transport pathways away from waste management areas. A preliminary food web pattern is described using results from ongoing and completed food habit studies. Biota possessing the greatest potential for introducing radionuclides into food chains leading to man include deer, rabbits, hares, waterfowl, honeybees and upland game birds and are discussed separately

  9. Patchiness in a minimal nutrient – phytoplankton model

    Indian Academy of Sciences (India)

    Srinivas

    increase in nutrient loading, which means the progress of eutrophication, makes the system converge to a stable equilibrium state. The return to homogeneous distribution means that adoption of the two-component model with nutrients and phytoplankton is one of the possible ways to avoid continuing limit-cycle oscillations ...

  10. Nutrient use efficiency in the food chain of China

    NARCIS (Netherlands)

    Ma, L.

    2014-01-01

      Key words: Nitrogen, phosphorus, food chain, food pyramid, food system, food security, food cost, environmental impacts, nutrient cycling, nutrient management

    Nitrogen (N) and phosphorus (P) fertilizer applications have greatly contributed to the increased

  11. Digestate and ash as alternatives to conventional fertilisers: Benefits and threats to soil biota

    Science.gov (United States)

    Marshall, Rachel; Lag-Brotons, Alfonso J.; Herbert, Ben; Hurst, Lois; Ostle, Nick; Dodd, Ian C.; Quinton, John; Surridge, Ben; Aiouache, Farid; Semple, Kirk T.

    2017-04-01

    Recovering energy and nutrients from waste offers opportunities to tackle issues of energy and food security whilst simultaneously improving waste management. Waste materials from the bioenergy industry potentially contain valuable resources for use in agriculture and there is growing evidence to suggest that the use of digestate, from anaerobic digestion, and biomass ash from incineration processes could contribute to improving soil health and nutrition. The work presented here is part of the Adding Value to Ash and Digestate (AVAnD) project which looks at the impacts of digestate and ash blends on soil fertility, crop yields and soil health. Whilst increased crop productivity is one of the essential indicators of the success of these alternative soil amendments; it is important that the impacts on soil biological function is understood. Field and lab experiments were conducted with a number of different fertiliser treatments, including conventional fertiliser (urea and superphosphate), digestate from two contrasting feedstocks, ash material and ash-digestate blends. Looking across different biological scales from soil microbe to soil macro-fauna, this work examines the benefits and threats to soil biota arising from the use of ash-digestate fertilisers in agriculture. Measurements of microbial respiration and biomass (by chloroform fumigation) and community composition (by phospholipid fatty acid analysis) were made at different timescales (days/weeks). Data from these studies demonstrates that none of the soil amendments decreased microbial activity or biomass in the short term (t= 1 month). Additions of both conventional fertilisers and the fertilisers derived from waste stimulated microbial activity with significantly higher respiration observed from the digestate based treatments. Digestate-based treatments also resulted in higher soil microbial biomass and differential effects were observed between digestate amendments with and without ash. These results

  12. ORIGIN AND EVOLUTION OF CONTINENTAL BIOTAS: SPECIATION AND HISTORICAL CONGRUENCE WITHIN THE AUSTRALIAN AVIFAUNA.

    Science.gov (United States)

    Cracraft, Joel

    1986-09-01

    Factors governing the origin and evolution of continental biotas were investigated using an analysis of speciation patterns within the Australian avifauna. Phylogenetic relationships within seven lineages of birds were analyzed by numerical cladistic techniques applied to data sets of morphological characters. These relationships revealed extensive congruence among the spatial and temporal histories of lineages whose species are endemic to common areas of endemism. A general hypothesis is constructed to explain this congruence in which widespread biotas are postulated to have been partitioned into areas of endemism by the origin of geomorphological and/or ecological-climatic barriers. Congruence in these phylogenetic patterns of differentiation suggests the following historical pattern of interrelationships for areas of endemism along the northern and eastern coasts of Australia: (Kimberley Plateau + Arnhem Land) + ([New Guinea + Cape York Peninsula] + [Atherton Plateau + Eastern Coastal Rainforest]). Likewise, this study indicates that the arid interior avifauna was segregated into two closely related biotas (Eastern and Western Desert biotas) by the Eyrean Barrier. These biotas are, in turn, related to a more mesic avifauna that was itself subdivided into areas of endemism located in the Southwest and Southeast corners of the continent. © 1986 The Society for the Study of Evolution.

  13. Bioaccumulation factor of 137Cs in some marine biotas from West Bangka Indonesia

    International Nuclear Information System (INIS)

    Suseno, Heny

    2014-01-01

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34

  14. Bioaccumulation factor of 137Cs in some marine biotas from West Bangka Indonesia

    Science.gov (United States)

    Suseno, Heny

    2014-03-01

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34.

  15. Bioaccumulation factor of {sup 137}Cs in some marine biotas from West Bangka Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Suseno, Heny, E-mail: henis@batan.go.id [Radioactive Waste Technology Center - The Indonesia Nuclear Energy Agency (BATAN) (Indonesia)

    2014-03-24

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34.

  16. Differential contribution of soil biota groups to plant litter decomposition as mediated by soil use

    Directory of Open Access Journals (Sweden)

    Ricardo A. Castro-Huerta

    2015-03-01

    Full Text Available Plant decomposition is dependant on the activity of the soil biota and its interactions with climate, soil properties, and plant residue inputs. This work assessed the roles of different groups of the soil biota on litter decomposition, and the way they are modulated by soil use. Litterbags of different mesh sizes for the selective exclusion of soil fauna by size (macro, meso, and microfauna were filled with standardized dried leaves and placed on the same soil under different use intensities: naturalized grasslands, recent agriculture, and intensive agriculture fields. During five months, litterbags of each mesh size were collected once a month per system with five replicates. The remaining mass was measured and decomposition rates calculated. Differences were found for the different biota groups, and they were dependant on soil use. Within systems, the results show that in the naturalized grasslands, the macrofauna had the highest contribution to decomposition. In the recent agricultural system it was the combined activity of the macro- and mesofauna, and in the intensive agricultural use it was the mesofauna activity. These results underscore the relative importance and activity of the different groups of the edaphic biota and the effects of different soil uses on soil biota activity.

  17. Upper Clear Creek watershed aquatic chemistry and biota surveys, 2004-5, Whiskeytown National Recreation Area, Shasta County, California

    Science.gov (United States)

    Wulff, Marissa L.; May, Jason T.; Brown, Larry R.

    2012-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service and Whiskeytown National Recreation Area, performed a comprehensive aquatic biota survey of the upper Clear Creek watershed, Shasta County, California, during 2004-5. Data collected in this study can provide resource managers with information regarding aquatic resources, watershed degradation, and regional biodiversity within Whiskeytown National Recreation Area. Surveys of water chemistry, bed-sediment chemistry, algae assemblages, benthic macroinvertebrate assemblages, aquatic vertebrate assemblages, in-stream habitat characteristics, and sediment heterogeneity were conducted at 17 stream sites during both 2004 and 2005, with an additional 4 sites surveyed in 2005. A total of 67 bed-sediment samples were analyzed for major and trace inorganic element concentrations. Forty-six water samples were analyzed for trace metals and nutrients. A total of 224 taxa of invertebrates were collected during these surveys. Eleven fish species, seven of which were native, and two species of larval amphibians, were collected. A total of 24 genera of soft algae and 159 taxa of diatoms were identified. To date, this survey represents the most comprehensive inventory of aquatic resources within Whiskeytown National Recreation Area, and this information can serve as a baseline for future monitoring efforts and to inform management decisions.

  18. Insects, infestations and nutrient fluxes

    Science.gov (United States)

    Michalzik, B.

    2012-04-01

    Forest ecosystems are characterized by a high temporal and spatial variability in the vertical transfer of energy and matter within the canopy and the soil compartment. The mechanisms and controlling factors behind canopy processes and system-internal transfer dynamics are imperfectly understood at the moment. Seasonal flux diversities and inhomogeneities in throughfall composition have been reported from coniferous and deciduous forests, and in most cases leaf leaching has been considered as principle driver for differences in the amount and quality of nutrients and organic compounds (Tukey and Morgan 1963). Since herbivorous insects and the processes they initiate received less attention in past times, ecologists now emphasize the need for linking biological processes occurring in different ecosystem strata to explain rates and variability of nutrient cycling (Bardgett et al. 1998, Wardle et al. 2004). Consequently, herbivore insects in the canopies of forests are increasingly identified to play an important role for the (re)cycling and availability of nutrients, or, more generally, for the functioning of ecosystems not only in outbreak situations but also at endemic (non-outbreak) density levels (Stadler et al. 2001, Hunter et al. 2003). Before, little attention was paid to insect herbivores when quantifying element and energy fluxes through ecosystems, although the numerous and different functions insects fulfill in ecosystems (e.g. as pollinators, herbivores or detritivores) were unanimously recognized (Schowalter 2000). Amongst the reasons for this restraint was the argument that the total biomass of insects tends to be relatively low compared to the biomass of trees or the pool of soil organic matter (Ohmart et al. 1983). A second argument which was put forward to justify the inferior role of insects in nutrient cycling were the supposed low defoliation losses between 5-10% of the annual leaf biomass, or net primary production, due to insect herbivory under

  19. Studies on the estimation of radiation dose to typical non human biota around Kaiga nuclear power plant

    International Nuclear Information System (INIS)

    Selvi, B.S.; Joshi, R.M.; Ajith, T.L.; Ravi, P.M.

    2008-01-01

    It is necessary to prove exclusively that biota is sufficiently protected from ionizing radiation since pathway leading to biota exposure is quite different compared to that for human being and non human biota has access to contaminated areas while human access is limited. The radiation from purely natural sources may be a useful benchmark since radiation at these levels is tolerated by biota. This paper presents the estimation of radiation dose to typical members of biota around Kaiga site, which includes a herbivorous mammalian species (cow), one avio fauna (pigeon), one burrowing animal (earthworm) and an aquatic animal (fish). The internal and external doses to species from naturally occurring radio nuclides were evaluated from concentrations of radio nuclides in soil, air, water and dietary items and the relevant concentration factors. An attempt is made for the evaluation of dose to above biota from reactor originated radio nuclides. The study identifies the most significant radionuclide, most significant pathway leading to radiological risk to member of biota from natural sources and reactor-produced radionuclides. From the computed dose to biota per unit release from reactor, study identifies the significant radionuclide and pathways for reactor produced radionuclides. The study conclusively proves that biota dose from reactor produced radionuclides from KGS is negligible. (author)

  20. Comparative analysis of doses to aquatic biota in water bodies impacted by radioactive contamination

    International Nuclear Information System (INIS)

    Kryshev, A.I.; Sazykina, T.G.

    2012-01-01

    Comparative analysis of doses to the reference species of freshwater biota was performed for the following water bodies in Russia or former USSR: Chernobyl NPPs cooling pond, Lakes Uruskul and Berdenish located in the Eastern Urals Radioactive Trace, Techa River, Yenisei River. It was concluded that the doses to biota were considerably different in the acute and chronic periods of radioactive contamination. The most vulnerable part of all considered aquatic ecosystems was benthic trophic chain. A numerical scale on the “dose rate – effects” relationships for fish was formulated. Threshold dose rates above which radiation effects can be expected in fish were evaluated to be the following: 1 mGy d −1 for appearance of the first morbidity effects in fish; 5 mGy d −1 for the first negative effects on reproduction system; 10 mGy d −1 for the first effects on life shortening of fish. The results of dose assessment to biota were compared with the scale “dose rate – effects” and the literature data on the radiobiological effects observed in the considered water bodies. It was shown that in the most contaminated water bodies the dose rates were high enough to cause the radiobiological effects in fish. - Highlights: ► Comparative analysis of dose rates to biota in different water bodies was performed. ► A numerical scale on the dose rates – effects relationships for fish was formulated. ► Results of assessment of exposure to biota were compared with the dose rates – effects scale. ► In the most contaminated water bodies the doses were high enough to cause radiobiological effects in fish. ► Current dose rates to biota in all considered water bodies are below the safety level of 1 mGy/day.

  1. A program in global biology. [biota-environment interaction important to life

    Science.gov (United States)

    Mooneyhan, D. W.

    1983-01-01

    NASA's Global Biology Research Program and its goals for greater understanding of planetary biological processes are discussed. Consideration is given to assessing major pathways and rates of exchange of elements such as carbon and nitrogen, extrapolating local rates of anaerobic activities, determining exchange rates of ocean nutrients, and developing models for the global cycles of carbon, nitrogen, sulfur, and phosphorus. Satellites and sensors operating today are covered: the Nimbus, NOAA, and Landsat series. Block diagrams of the software and hardware for a typical ground data processing and analysis system are provided. Samples of the surface cover data achieved with the Advanced Very High Resolution Radiometer, the Multispectral Scanner, and the Thematic Mapper are presented, as well as a productive capacity model for coastal wetlands. Finally, attention is given to future goals, their engineering requirements, and the necessary data analysis system.

  2. Dust Fertilization of the Western Atlantic Biota: a Biochemical Model

    Science.gov (United States)

    Holmes, C. W.

    2017-12-01

    Every year an estimated 50 million tons of African dust reaches the Western Atlantic. This dust is composed of quartz sand, clay, and a mixture of quartz and clay particles agglutinated with micronutrient enriched ferruginous cement. However, whether it is friend or foe to biochemical systems is a matter of conjecture. Corals are ideal recorders of changing conditions as the layers can be dated so that the record of chemical changes is easily assessed. There is extensive shallow-and deep water coral development bordering the Florida Straits. The changes in trace element chemistry within these corals show a positive relationship with the African dust record. Recently, it has been demonstrated that many of the metals contained within the dust are necessary micronutrients in the fertilization of plankton. Using the results of these studies, a biochemical model has been constructed. This model suggests a path from inorganic dust through microbial transformation to micronutrient enzymes (i.e. Cd-enriched carbonic anahydrase) and carbonate precipitation on the Bahamian Banks. It is estimated that more than ten million metric tons of this fine, metal-rich sediment is formed each year. However, for much of this sediment, its deposition is temporary, as it is transported into the Florida Straits yearly by tropical cyclones. This metal-enriched fine carbonate becomes nutrients for phytoplankton, providing food for the corals, both shallow and deep.

  3. Essential Nutrients, Feed Classification and Nutrient Content of Feeds

    OpenAIRE

    Hall, John Burton, 1960-; Seay, William W.; Baker, Scott M., 1968-

    2005-01-01

    The cow-calf herd's primary source of nutrition is forages, but forages are variable in nutrient content. By knowing the nutrient content of their base forages, producers can then identify the deficient nutrients that need to be supplemented.

  4. Menstrual Cycle

    Science.gov (United States)

    ... To receive General email updates Enter email Submit Menstrual Cycle The menstrual cycle is the hormonal process ... Preventing problems with your menstrual cycle View more Menstrual Cycle resources Related information Endometriosis Infertility Polycystic ovary ...

  5. Arbuscular mycorrhizal fungal species differ in their effect on nutrient leaching

    NARCIS (Netherlands)

    Köhl, Luise; van der Heijden, Marcel G A

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi have been shown to play a crucial role in nutrient cycling and can reduce nutrient losses after rain induced leaching events. It is still unclear whether nutrient leaching losses vary depending on the AM fungal taxa that are present in soil. Using experimental

  6. Seasonal variability in nutrient regeneration by mussel Mytilus edulis rope culture in oligotrophic systems

    NARCIS (Netherlands)

    Jansen, H.M.; Strand, O.; Strohmeier, T.; Krogness, C.; Verdegem, M.C.J.; Smaal, A.C.

    2011-01-01

    Blue mussel Mytilus edulis cultures contribute to nutrient cycling in coastal ecosystems. Mussel populations filter particulate nutrients from the water column and inorganic nutrients are regenerated by excretion of metabolic wastes and decomposition of (pseudo-)faeces. The objective of this study

  7. Nutrients that limit growth in the ocean.

    Science.gov (United States)

    Bristow, Laura A; Mohr, Wiebke; Ahmerkamp, Soeren; Kuypers, Marcel M M

    2017-06-05

    Phytoplankton form the basis of the marine food web and are responsible for approximately half of global carbon dioxide (CO2) fixation (∼ 50 Pg of carbon per year). Thus, these microscopic, photosynthetic organisms are vital in controlling the atmospheric CO2 concentration and Earth's climate. Phytoplankton are dependent on sunlight and their CO2-fixation activity is therefore restricted to the upper, sunlit surface ocean (that is, the euphotic zone). CO2 usually does not limit phytoplankton growth due to its high concentration in seawater. However, the vast majority of oceanic surface waters are depleted in inorganic nitrogen, phosphorus, iron and/or silica; nutrients that limit primary production in the ocean (Figure 1). Phytoplankton growth is mainly supported by either the recycling of nutrients or by reintroduction of nutrients from deeper waters by mixing. A small percentage of primary production, though, is fueled by 'external' or 'new' nutrients and it is these nutrients that determine the amount of carbon that can be sequestered long term in the deep ocean. For most nutrients such as phosphorus, iron, and silica, the external supply is limited to atmospheric deposition and/or coastal and riverine inputs, whereas their main sink is the sedimentation of particulate matter. Nitrogen, however, has an additional, biological source, the fixation of N2 gas, as well as biological sinks via the processes of denitrification and anammox. Despite the comparatively small contributions to the overall turnover of nutrients in the ocean, it is these biological processes that determine the ocean's capacity to sequester CO2 from the atmosphere on time scales of ocean circulation (∼ 1000 years). This primer will highlight shifts in the traditional paradigms of nutrient limitation in the ocean, with a focus on the uniqueness of the nitrogen cycling and its biological sources and sinks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Spatial and temporal trends of contaminants in terrestrial biota from the Canadian Arctic

    International Nuclear Information System (INIS)

    Gamberg, Mary; Braune, Birgit; Davey, Eric; Elkin, Brett; Hoekstra, Paul F.; Kennedy, David; Macdonald, Colin; Muir, Derek; Nirwal, Amar; Wayland, Mark; Zeeb, Barbara

    2005-01-01

    Contaminants in the Canadian Arctic have been studied over the last twelve years under the guidance of the Northern Contaminants Program. This paper summarizes results from that program from 1998 to 2003 with respect to terrestrial animals in the Canadian Arctic. The arctic terrestrial environment has few significant contaminant issues, particularly when compared with freshwater and marine environments. Both current and historical industrial activities in the north may have a continuing effect on biota in the immediate area, but effects tend to be localized. An investigation of arctic ground squirrels at a site in the Northwest Territories that had historically received applications of DDT concluded that DDT in arctic ground squirrels livers was the result of contamination and that this is an indication of the continuing effect of a local point source of DDT. Arsenic concentrations were higher in berries collected from areas around gold mines in the Northwest Territories than from control sites, suggesting that gold mining may significantly affect arsenic levels in berries in the Yellowknives Dene traditional territory. Although moose and caribou from the Canadian Arctic generally carry relatively low contaminant burdens, Yukon moose had high renal selenium concentrations, and moose and some woodland caribou from the same area had high renal cadmium levels, which may put some animals at risk of toxicological effects. Low hepatic copper levels in some caribou herds may indicate a shortage of copper for metabolic demands, particularly for females. Similarities in patterns of temporal fluctuations in renal element concentrations for moose and caribou suggest that environmental factors may be a major cause of fluctuations in renal concentrations of some elements. Concentrations of persistent organochlorines and metals in beaver and muskrat from the Northwest Territories, and carnivores from across the Canadian Arctic were very low and considered normal for terrestrial

  9. In situ evaluation of wastewater discharges and the bioavailability of contaminants to marine biota

    Energy Technology Data Exchange (ETDEWEB)

    Maranho, L.A., E-mail: lmaranho@gmail.com [Andalusian Centre of Marine Science and Technology (CACYTMAR), University of Cádiz, Polygon Río San Pedro, s/n, 11510 Puerto Real, Cádiz (Spain); Physical Chemical Department, Faculty of Marine and Environmental Sciences, University of Cádiz, Polygon Río San Pedro, s/n, 11510 Puerto Real, Cádiz (Spain); André, C. [Emerging Methods, Aquatic Contaminants Research Division, Environment Canada, 105 McGill Street, 7th floor, H2Y 2E7 Montreal, Quebec (Canada); DelValls, T.A. [Physical Chemical Department, Faculty of Marine and Environmental Sciences, University of Cádiz, Polygon Río San Pedro, s/n, 11510 Puerto Real, Cádiz (Spain); Gagné, F. [Emerging Methods, Aquatic Contaminants Research Division, Environment Canada, 105 McGill Street, 7th floor, H2Y 2E7 Montreal, Quebec (Canada); Martín-Díaz, M.L. [Andalusian Centre of Marine Science and Technology (CACYTMAR), University of Cádiz, Polygon Río San Pedro, s/n, 11510 Puerto Real, Cádiz (Spain); Physical Chemical Department, Faculty of Marine and Environmental Sciences, University of Cádiz, Polygon Río San Pedro, s/n, 11510 Puerto Real, Cádiz (Spain)

    2015-12-15

    Marine sediment quality of wastewater discharges areas was determined by using in situ caged clams Ruditapes philippinarum taking into account the seasonality. Clams were caged in sediment directly affected by wastewater discharges at four sites (P1, P2, P3, P4) at the Bay of Cádiz (SW, Spain), and one reference site (P6). Exposure to contaminated sediments was confirmed by measurement of metals and As, PAH, pharmaceutical products and surfactants (SAS) in bottom sediments. Biological effects were determined by following biomarkers of exposure (activities of 7-ethoxyresorufin O-deethylase — EROD, dibenzylfluorescein dealkylase — DBF, glutathione S-transferase — GST, glutathione peroxidase — GPX, glutathione reductase — GR and acetylcholinesterase — AChE), effects (lysosomal membrane stability — LMS, DNA damage and lipid peroxidation — LPO), energy status (total lipids — TLP and mitochondrial electron transport — MET), and involved in the mode of action of pharmaceutical products (monoamine oxidase activity — MAO, alkali-labile phosphates — ALP levels and cyclooxygenase activity — COX). In winter, urban effluents were detoxified by phase I biotransformation (CYP3A-like activity), phase II (GST), and the activation of antioxidant defence enzymes (GR). Urban effluents lead to the detoxification metabolism (CYP1A-like), oxidative effects (LPO and DNA damage), neurotoxicity (AChE) and neuroendocrine disruption (COX and ALP levels) involved in inflammation (P1 and P2) and changes in reproduction as spawning delay (P3 and P4) in clams exposed in summer. Adverse effects on biota exposed to sediment directly affected by wastewater discharges depend on the chemical contamination level and also on the reproductive cycle according to seasonality. - Highlights: • Sediment quality of wastewater discharges evaluated by caged clams R. philippinarum • Exposure was confirmed by measurement of metal and organic compounds in sediments. • Winter

  10. Effect of long term cropping hybrid sorrel (Rumex patientia x Rumex tianshanicus) on soil biota

    Czech Academy of Sciences Publication Activity Database

    Heděnec, Petr; Novotný, D.; Usťak, S.; Honzík, R.; Váňa, V.; Petříková, V.; Frouz, Jan

    2015-01-01

    Roč. 78, July (2015), s. 92-98 ISSN 0961-9534 R&D Projects: GA MŠk(CZ) 7E08081 Institutional support: RVO:60077344 Keywords : basal soil respiration * composition of soil biota * hybrid sorrel * microbial biomass C * specific microbial respiration (qCO2) Subject RIV: DF - Soil Science Impact factor: 3.249, year: 2015

  11. Microplastics as Vectors for Environmental Contaminants : Exploring Sorption, Desorption, and Transfer to Biota

    DEFF Research Database (Denmark)

    Hartmann, Nanna B.; Rist, Sinja; Bodin, Julia

    2017-01-01

    The occurrence and effects of microplastics (MPs) in the aquatic environment are receiving increasing attention. In addition to their possible direct adverse effects on biota, the potential role of MPs as vectors for hydrophobic organic chemicals (HOCs), compared to natural pathways, is a topic...

  12. Roles of soil biota and biodiversity in soil environment – A concise communication

    Directory of Open Access Journals (Sweden)

    Suleiman Usman

    2016-10-01

    Full Text Available Soil biota (the living organisms in soil plays an important role in soil development and soil formation. They are the most important component of soil organic matter decomposition and behave efficiently in the development and formation of soil structure and soil aggregate. Their biodiversity provides many functional services to soil and soil components. They help in dissolving verities of plant and animal materials, which could left as decayed organic matter at the surface soil. Understanding the vital role of soil organisms would undoubtedly helps to increase food production and reduces poverty, hunger and malnutrition. Soil biota and biodiversity research in sub-Saharan Africa would play an important role in sustaining food security, environmental health, water quality and forest regeneration. This paper, briefly highlighted some of the biological functions of soil biota and suggests that proper understandings of biota and their biodiversity in soil environment would provide ways to get better understanding of soil health, soil function, soil quality and soil fertility under sustainable soil management activities in agricultural production.

  13. Concentration factors 226Ra, 210Pb and 90Sr in the biota of the Sava river

    International Nuclear Information System (INIS)

    Vujnovicj, J.

    1977-01-01

    This work presents the results of identification of the concentration factor in the biota of the river Sava. Organisms of the water system have different abilities of concentration of radio nuclide. This ability is most highly expressed in plancton as the first link on the trophic chain. As the length of trat chain increases, the concentration of radionuclide in the organisms diminishes

  14. Accumulation of radionuclides in selected marine biota from Manjung coastal area

    Science.gov (United States)

    Abdullah, Anisa; Hamzah, Zaini; Saat, Ahmad; Wood, Ab. Khalik; Alias, Masitah

    2015-04-01

    Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 (226Ra), radium-228 (228Ra) and potassium-40 (40K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (Hin), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption.

  15. Crop rotations and poultry litter impact dynamic soil chemical properties and soil biota long-term

    Science.gov (United States)

    Dynamic soil physiochemical interactions with conservation agricultural practices and soil biota are largely unknown. Therefore, this study aims to quantify long-term (12-yr) impacts of cover crops, poultry litter, crop rotations, and conservation tillage and their interactions on soil physiochemica...

  16. Microplastics as Vectors for Environmental Contaminants : Exploring Sorption, Desorption, and Transfer to Biota

    DEFF Research Database (Denmark)

    Hartmann, Nanna B.; Rist, Sinja; Bodin, Julia

    2017-01-01

    of much debate. It is evident, however, that temporal and spatial variations of MP occurrence do (and will) occur. To further improve the estimations of the role of MPs as vectors for HOC transfer into biota under varying MP concentrations and environmental conditions, it is important to identify...

  17. Nestedness of Southern Ocean island biotas: ecological perspectives on a biogeographical conundrum

    NARCIS (Netherlands)

    Greve, M.; Gremmen, N.J.M.; Gaston, K.J.; Chown, S.L.

    2005-01-01

    Aim To use patterns of nestedness in the indigenous and non-indigenous biotas of the Southern Ocean islands to determine the influence of dispersal ability on biogeographical patterns, and the importance of accounting for variation in dispersal ability in their subsequent interpretation, especially

  18. Investigation on applicability of Biota dose assessment model to Japanese environment

    International Nuclear Information System (INIS)

    Kawaguchi, Isao; Takahashi, Tomoyuki; Uchida, Shigeo

    2008-01-01

    We examined applicability of established assessment tools to Japanese environment, which are developed to evaluate radiological impact for biota. In this study, we chose two assessment tools, the one is RESRAD-BIOTA which was developed by US-DOE, and the other is ERICA assessment tools which developed by EURATOM. We considered paddy field as the typical Asian environment and used maximum of global fallout nuclide concentrations which were monitored in Joetsu. From our trial calculation for general screening, Tier 1 of ERICA suggested that concentration of 137 Cs in aquatic systems is exceeded the screening level. On the other hand, RESRAD-BIOTA, concentration of 90 Sr, and terrestrial systems in ERICA were less than screening levels. Thus, we proceeded to apply the ERICA Tier 2 using with same parameter set in Tier 1, and found that each species was not exceeded the screening level. Finally, we calculated dosimetries of considerable species living in paddy field. We tested both tools and we adopted ERICA because of flexibility in body dimensions of adding organism. From our calculation, we concluded that graded approaches which are adopted in RESRAD-BIOTA and ERICA are effective to apply Japanese environment. (author)

  19. Concordant Biogeographic Patterns among Multiple Taxonomic Groups in the Mexican Freshwater Biota

    Science.gov (United States)

    Quiroz-Martínez, Benjamín; Álvarez, Fernando; Espinosa, Héctor; Salgado-Maldonado, Guillermo

    2014-01-01

    In this paper we analyse the degree of concordance in species richness and taxonomic distinctness (diversity) patterns among different freshwater taxonomic groups in order to test three long held patterns described in Mexican freshwater biogeography: 1. The aquatic biota of Mexico includes two distinct faunas, a rich Neotropical component in the south and a south-eastern region and a less rich Nearctic component towards central and northern latitudes of the country. 2. A hotspot of species richness and diversity has been recorded in the Usumacinta, including the Yucatan Peninsula. 3. The presence of two distinct biotas in Mexico, an eastern one distributed along the Gulf of Mexico slope, and a western one associated to the Pacific versant. We use species richness and taxonomic distinctness to explore patterns of diversity and how these patterns change between zoogeographical regions. This paper points out a clear separation between Neotropical and Nearctic drainage basins but also between eastern (Gulf of Mexico) and western (Pacific) drainage basins. Present data gives additional empirical support from freshwater biota for three long held beliefs regarding distributional patterns of the Mexican biota. The neotropical basins of Mexico are generally host to a richest and more diversified fauna, that includes more families, genera and species, compared to the less rich and less diverse fauna in the nearctic basins. PMID:25136979

  20. Pesticide Interactions with N source and Tillage: Effects on soil biota and ecosystem services

    DEFF Research Database (Denmark)

    Jensen, John; Petersen, Søren O; Elsgaard, Lars

    Pesticide effects on soil biota must be interpreted in the context of the specific management practice, including rotation, fertilization, tillage, and pest control. Tillage, foe example, has been shown to reduce earthworm populations by up to 80%, depending on timing and specific tillage techniq...

  1. Seven years of NeoBiota – the times, were they a changin’?

    Czech Academy of Sciences Publication Activity Database

    Kühn, I.; Pyšek, Petr; Kowarik, I.

    2017-01-01

    Roč. 36, č. 1 (2017), s. 57-69 ISSN 1619-0033 Grant - others:AV ČR(CZ) AP1002 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985939 Keywords : NeoBiota * journal * history Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology

  2. Modeling nutrient transports and exchanges of nutrients between shallow regions and the open Baltic sea in present and future climate.

    Science.gov (United States)

    Eilola, Kari; Rosell, Elin Almroth; Dieterich, Christian; Fransner, Filippa; Höglund, Anders; Meier, H E Markus

    2012-09-01

    We quantified horizontal transport patterns and the net exchange of nutrients between shallow regions and the open sea in the Baltic proper. A coupled biogeochemical-physical circulation model was used for transient simulations 1961-2100. The model was driven by regional downscaling of the IPCC climate change scenario A1B from two global General Circulation Models in combination with two nutrient load scenarios. Modeled nutrient transports followed mainly the large-scale internal water circulation and showed only small circulation changes in the future projections. The internal nutrient cycling and exchanges between shallow and deeper waters became intensified, and the internal removal of phosphorus became weaker in the warmer future climate. These effects counteracted the impact from nutrient load reductions according to the Baltic Sea Action Plan. The net effect of climate change and nutrient reductions was an increased net import of dissolved inorganic phosphorus to shallow areas in the Baltic proper.

  3. Nutrient Content Claims

    Science.gov (United States)

    ... 8, 2014 Articles from Diabetes Forecast® magazine: wcie-nutrition, . In this section Food What Can I Eat Food Tips Eating Out Quick Meal Ideas Cutting Back on Sodium Nutrient Content Claims Snacks Taking ...

  4. Experimental Studies on Plutonium Kinetics in Marine Biota

    International Nuclear Information System (INIS)

    Fowler, S.; Heyraud, M.; Beasley, T.M.

    1976-01-01

    Laboratory experiments were undertaken to measure plutonium flux through marine organisms and to clarify the pathways by which this important element is cycled in the marine environment. The use of a specially prepared isotope, plutonium-237, allowed measurements to be made with standard Nal(Tl) scintillation techniques. Mussels, shrimp and worms were allowed to accumulate plutonium-237 from sea water for up to 25 days. Accumulation by shrimp was relatively slow and the degree of uptake was strongly influenced by moulting. Cast moults contained large fractions of the shrimps ' plutonium content, indicating the high affinity of plutonium for surface areas. Only small amounts of the isotope in the moult are lost to water; hence, moulting is considered to be an important biological parameter in the biogeochemical cycling of plutonium. Mussels attained higher concentration factors than shrimp with most of the accumulated isotope (> 80%) located in the shell. Byssus threads often contained large fractions of the mussels' plutonium-237 content and reached concentration factors as high as 4100. Worms readily accumulated plutonium-237 in either the +4 or +6 state, reaching concentration factors of approximately 200, Retention studies indicated a relatively slow loss of plutonium-237 from all animals studied. In the case of mussels, a computed half-time for a large fraction of the animals plutonium content was of the order of 2 years. The more rapid loss from shrimp (Tb 1/2 = 1.5 months) was due principally to the large fraction of plutonium lost at moult. Food chain studies with shrimp indicated that tissue build-up via plutonium ingestion would be a slow process. Total excretion was not entirely a result of passing contaminated food through the gut; approximately 15% of the ingested plutonium was removed from the contaminated food and subsequently excreted by processes other than defaecation of labelled food. Ratios of four different plutonium isotopes used in

  5. Experimental studies on plutonium kinetics in marine biota

    International Nuclear Information System (INIS)

    Fowler, S.; Heyraud, M.; Beasley, T.M.

    1975-01-01

    Laboratory experiments were undertaken to measure plutonium flux through marine organisms and to clarify the pathways by which this important element is cycled in the marine environment. The use of a specially prepared isotope, plutonium-237, allowed measurements to be made with standard NaI(Tl) scintillation techniques. Mussels, shrimp and worms were allowed to accumulate plutonium-237 from seawater for up to 25 days. Accumulation by shrimp was relatively slow and the degree of uptake was strongly influenced by moulting. Cast moults contained large fractions of the shrimps' plutonium content, indicating the high affinity of plutonium for surface areas. Only small amounts of the isotope in the moult are lost to water; hence, moulting is considered to be an important biological parameter in the biogeochemical cycling of plutonium. Mussels attained higher concentration factors than shrimp with most of the accumulated isotope (>80%) located in the shell. Byssus threads often contained large fractions of the mussels' plutonium-237 content and reached concentration factors as high as 4100. Worms readily accumulated plutonium-237 in either the +4 or +6 state, reaching concentration factors of approximately 200. Retention studies indicated a relatively slow loss of plutonium-237 from all animals studied. In the case of mussels, a computed half-time for a large fraction of the animals' plutonium content was of the order of 2 years. The more rapid loss from shrimp (Tbsub(1/2)=1.5 months) was due principally to the large fraction of plutonium lost at moult. Food chain studies with shrimp indicated that tissue build-up via plutonium ingestion would be a slow process. Total excretion was not entirely a result of passing contaminated food through the gut; approximately 15% of the ingested plutonium was removed from the contaminated food and subsequently excreted by processes other than defaecation of labelled food. Ratios of four different plutonium isotopes used in the

  6. Global soil-climate-biome diagram: linking soil properties to climate and biota

    Science.gov (United States)

    Zhao, X.; Yang, Y.; Fang, J.

    2017-12-01

    As a critical component of the Earth system, soils interact strongly with both climate and biota and provide fundamental ecosystem services that maintain food, climate, and human security. Despite significant progress in digital soil mapping techniques and the rapidly growing quantity of observed soil information, quantitative linkages between soil properties, climate and biota at the global scale remain unclear. By compiling a large global soil database, we mapped seven major soil properties (bulk density [BD]; sand, silt and clay fractions; soil pH; soil organic carbon [SOC] density [SOCD]; and soil total nitrogen [STN] density [STND]) based on machine learning algorithms (regional random forest [RF] model) and quantitatively assessed the linkage between soil properties, climate and biota at the global scale. Our results demonstrated a global soil-climate-biome diagram, which improves our understanding of the strong correspondence between soils, climate and biomes. Soil pH decreased with greater mean annual precipitation (MAP) and lower mean annual temperature (MAT), and the critical MAP for the transition from alkaline to acidic soil pH decreased with decreasing MAT. Specifically, the critical MAP ranged from 400-500 mm when the MAT exceeded 10 °C but could decrease to 50-100 mm when the MAT was approximately 0 °C. SOCD and STND were tightly linked; both increased in accordance with lower MAT and higher MAP across terrestrial biomes. Global stocks of SOC and STN were estimated to be 788 ± 39.4 Pg (1015 g, or billion tons) and 63 ± 3.3 Pg in the upper 30-cm soil layer, respectively, but these values increased to 1654 ± 94.5 Pg and 133 ± 7.8 Pg in the upper 100-cm soil layer, respectively. These results reveal quantitative linkages between soil properties, climate and biota at the global scale, suggesting co-evolution of the soil, climate and biota under conditions of global environmental change.

  7. Nutrient sequestration in Aquitaine lakes (SW France) limits nutrient flux to the coastal zone

    Science.gov (United States)

    Buquet, Damien; Anschutz, Pierre; Charbonnier, Céline; Rapin, Anne; Sinays, Rémy; Canredon, Axel; Bujan, Stéphane; Poirier, Dominique

    2017-12-01

    Oligotrophic coastal zones are disappearing from increased nutrient loading. The quantity of nutrients reaching the coast is determined not only by their original source (e.g. fertilizers used in agriculture, waste water discharges) and the land use, but also by the pathways through which nutrients are cycled from the source to the river mouth. In particular, lakes sequester nutrients and, hence, reduce downstream transfer of nutrients to coastal environments. Here, we quantify the impact of Aquitaine great lakes on the fluxes of dissolved macro-nutrients (N, P, Si) to the Bay of Biscay. For that, we have measured nutrient concentrations and fluxes in 2014 upstream and downstream lakes of Lacanau and Carcans-Hourtin, which belongs to the catchment of the Arcachon Bay, which is the largest coastal lagoon of the Bay of Biscay French coast. Data were compared to values obtained from the Leyre river, the main freshwater and nutrient source for the lagoon. Results show that processes in lakes greatly limit nutrient flux to the lagoon compared to fluxes from Leyre river, although the watershed is similar in terms of land cover. In lakes, phosphorus and silicon are trapped for long term in the sediment, silicon as amorphous biogenic silica and phosphorus as organic P and P associated with Fe-oxides. Nitrogen that enters lakes mostly as nitrate is used for primary production. N is mineralized in the sediment; a fraction diffuses as ammonium. N2 production through benthic denitrification extracts only 10% of dissolved inorganic nitrogen from the aquatic system. The main part is sequestered in organic-rich sediment that accumulates below 5 m depth in both lakes.

  8. Nutrient synchrony in preruminant calves

    NARCIS (Netherlands)

    Borne, van den J.J.G.C.

    2006-01-01

    In animal nutrition, the nutrient composition of the daily feed supply is composed to match the nutrient requirements for the desired performance. The time of nutrient availability within a day is usually considered not to affect the fate of nutrients. The aim of this thesis was to evaluate effects

  9. Nutrient uptake dynamics across a gradient of nutrient concentrations and ratios at the landscape scale

    Science.gov (United States)

    Gibson, Catherine A.; O'Reilly, Catherine M.; Conine, Andrea L.; Lipshutz, Sondra M.

    2015-02-01

    Understanding interactions between nutrient cycles is essential for recognizing and remediating human impacts on water quality, yet multielemental approaches to studying nutrient cycling in streams are currently rare. Here we utilized a relatively new approach (tracer additions for spiraling curve characterization) to examine uptake dynamics for three essential nutrients across a landscape that varied in absolute and relative nutrient availability. We measured nutrient uptake for soluble reactive phosphorous, ammonium-nitrogen, and nitrate-nitrogen in 16 headwater streams in the Catskill Mountains, New York. Across the landscape, ammonium-nitrogen and soluble reactive phosphorus had shorter uptake lengths and higher uptake velocities than nitrate-nitrogen. Ammonium-nitrogen and soluble reactive phosphorus uptake velocities were tightly correlated, and the slope of the relationship did not differ from one, suggesting strong demand for both nutrients despite the high ambient water column dissolved inorganic nitrogen: soluble reactive phosphorus ratios. Ammonium-nitrogen appeared to be the preferred form of nitrogen despite much higher nitrate-nitrogen concentrations. The uptake rate of nitrate-nitrogen was positively correlated with ambient soluble reactive phosphorus concentration and soluble reactive phosphorus areal uptake rate, suggesting that higher soluble reactive phosphorus concentrations alleviate phosphorus limitation and facilitate nitrate-nitrogen uptake. In addition, these streams retained a large proportion of soluble reactive phosphorus, ammonium-nitrogen, and nitrate-nitrogen supplied by the watershed, demonstrating that these streams are important landscape filters for nutrients. Together, these results (1) indicated phosphorus limitation across the landscape but similarly high demand for ammonium-nitrogen and (2) suggested that nitrate-nitrogen uptake was influenced by variability in soluble reactive phosphorus availability and preference for

  10. Methodology for Estimating Radiation Dose Rates to Freshwater Biota Exposed to Radionuclides in the Environment

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G.

    1993-01-01

    The purpose of this report is to present a methodology for evaluating the potential for aquatic biota to incur effects from exposure to chronic low-level radiation in the environment. Aquatic organisms inhabiting an environment contaminated with radioactivity receive external radiation from radionuclides in water, sediment, and from other biota such as vegetation. Aquatic organisms receive internal radiation from radionuclides ingested via food and water and, in some cases, from radionuclides absorbed through the skin and respiratory organs. Dose rate equations, which have been developed previously, are presented for estimating the radiation dose rate to representative aquatic organisms from alpha, beta, and gamma irradiation from external and internal sources. Tables containing parameter values for calculating radiation doses from selected alpha, beta, and gamma emitters are presented in the appendix to facilitate dose rate calculations. The risk of detrimental effects to aquatic biota from radiation exposure is evaluated by comparing the calculated radiation dose rate to biota to the U.S. Department of Energy's (DOE's) recommended dose rate limit of 0.4 mGy h{sup -1} (1 rad d{sup -1}). A dose rate no greater than 0.4 mGy h{sup -1} to the most sensitive organisms should ensure the protection of populations of aquatic organisms. DOE's recommended dose rate is based on a number of published reviews on the effects of radiation on aquatic organisms that are summarized in the National Council on Radiation Protection and Measurements Report No. 109 (NCRP 1991). The literature identifies the developing eggs and young of some species of teleost fish as the most radiosensitive organisms. DOE recommends that if the results of radiological models or dosimetric measurements indicate that a radiation dose rate of 0.1 mGy h{sup -1} will be exceeded, then a more detailed evaluation of the potential ecological consequences of radiation exposure to endemic

  11. Integrated Urban Nutrient Management

    Science.gov (United States)

    Nhapi, I.; Veenstra, S.; Siebel, M. A.; Gijzen, H. J.

    Most cities, especially from the developing countries, are facing serious problems with the management of nutrients, necessitating an urgent review of current waste management systems. Whilst highly efficient technologies are available, the inclusion of these in a well-thought out and systematic approach is necessary to contain the nutrient influxes and outfluxes from towns. Five intervention measures are proposed in this paper. The first is to manage the use and generation of nutrients by drastically minimising water consumption and employing other cleaner production approaches. The second deals with the optimal reuse of nutrients and water at the smallest possible level, like at the household and on-plot level. The second option is to covert the waste into something useful for reuse, and, where not possible, to something which is envi- ronmentally neutral. This involves treatment, but applying technologies that makes the best use of side products via reuse. Where the first three options will have failed, two least preferred options could be used. Waste can be dispersed or diluted to enhance self-purification capacities of downstream water bodies. The last option is to store the wastewater for some parts of the year when there is water shortage to allow for polishing during the standing period. The success of urban nutrient planning requires an integrated approach, proving specific solutions to specific situations. This, in turn, requires appropriate institutional responses.

  12. Global nutrient transport in a world of giants.

    Science.gov (United States)

    Doughty, Christopher E; Roman, Joe; Faurby, Søren; Wolf, Adam; Haque, Alifa; Bakker, Elisabeth S; Malhi, Yadvinder; Dunning, John B; Svenning, Jens-Christian

    2016-01-26

    The past was a world of giants, with abundant whales in the sea and large animals roaming the land. However, that world came to an end following massive late-Quaternary megafauna extinctions on land and widespread population reductions in great whale populations over the past few centuries. These losses are likely to have had important consequences for broad-scale nutrient cycling, because recent literature suggests that large animals disproportionately drive nutrient movement. We estimate that the capacity of animals to move nutrients away from concentration patches has decreased to about 8% of the preextinction value on land and about 5% of historic values in oceans. For phosphorus (P), a key nutrient, upward movement in the ocean by marine mammals is about 23% of its former capacity (previously about 340 million kg of P per year). Movements by seabirds and anadromous fish provide important transfer of nutrients from the sea to land, totalling ∼150 million kg of P per year globally in the past, a transfer that has declined to less than 4% of this value as a result of the decimation of seabird colonies and anadromous fish populations. We propose that in the past, marine mammals, seabirds, anadromous fish, and terrestrial animals likely formed an interlinked system recycling nutrients from the ocean depths to the continental interiors, with marine mammals moving nutrients from the deep sea to surface waters, seabirds and anadromous fish moving nutrients from the ocean to land, and large animals moving nutrients away from hotspots into the continental interior.

  13. Lake biota response to human impact and local climate during the last 200 years: A multi-proxy study of a subalpine lake (Tatra Mountains, W Carpathians).

    Science.gov (United States)

    Hamerlík, Ladislav; Dobríková, Daniela; Szarlowicz, Katarzyna; Reczynski, Witold; Kubica, Barbara; Šporka, Ferdinand; Bitušík, Peter

    2016-03-01

    Element content, loss-on-ignition, chironomid analysis and (210)Pb dating were applied on a sediment core from a subalpine Tatra lake (Popradské pleso) to reveal the response of aquatic biota to eutrophication induced by human activities in the lake catchment. The lead dating indicates that the 0-8 cm section of the core represents the past ca 200 years, ending at ~1814 AD. Comparing the key changes of the proxies with human activities that are historically well documented, four phases of the recent lake development were distinguished: (1) a pre-tourism phase, (2) a phase of increasing touristic activity and early cottage development, (3) a phase of eutrophication, and (4) a phase of post-eutrophication. Neither touristic activity, nor early cottage development around the lake (1st and 2nd phases) had considerable influence on the chironomid assemblage structure or organic content of the lake. The most significant change both in chironomid assemblage structure and loss-on-ignition occurred during the 3rd phase, when a big tourist hotel was built close by the lake and started contaminating it via direct wastewater input. However, the structure of the chironomid assemblage has not changed significantly over time and the dominating taxa remained the same during the whole period. Parallel with the nutrient signal of the paleo assemblage, a secondary signal has been identified as the ratio of rheophilic taxa on total abundance that did not correlate with the sediment's organic content, and is most likely driven by local climatic oscillations. Changes of most of metal elements concentrations reflected rather bigger scale changes of industrial activities than local scale human disturbances. Our results indicate that hydromorphological properties can moderate the impact of organic pollution on the lake biota. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. SUPPRESSION ABILITY OF CRUDE EXTRACT DERIVED FROM MARINE BIOTA AGAINST FUSARIUM OXYSPORUM F.SP. VANILLAE

    Directory of Open Access Journals (Sweden)

    I Ketut Suada

    2010-06-01

    Full Text Available The objective of this research was to investigate suppression ability of marine biota extracts against Fusarium oxysporum f.sp. vanillae of vanilla stem rot. Samples were collected at intertidal zones and in the depth of 1-7 m from seven beaches in Bali. Screening of active compounds of biota extracts were conducted using inhibition zone of well diffusion method on Potato Dextrose Agar (PDA. The extract was tested in-vitro in PDA medium using completely randomized design with three replicates. The methanolic extract of Aglaophenia sp. was able to suppress the growth of F. oxysporum f.sp. vanillae effectively, with minimum inhibition concentration (MIC of 0.05 %. The extract inhibited colony growth diameter and total mycelial dry weight.

  15. Total petroleum hydrocarbons in edible marine biota from Northern Persian Gulf.

    Science.gov (United States)

    Nozar, Seyedeh Laili Mohebbi; Pauzi, Mohamad Zakaria; Salarpouri, Ali; Daghooghi, Behnam; Salimizadeh, Maryam

    2015-04-01

    To provide a baseline information for consumer's health, distribution of total petroleum hydrocarbons in 18 edible marine biota species from northern Persian Gulf was evaluated. The samples were purchased from fish market of Hormozgan Province, South of Iran. Marine biota samples included different species with various feeding habits and were analyzed based on ultraviolet florescence spectroscopy. Petroleum hydrocarbons showed narrow variation, ranging from 0.67 to 3.36 μg/g dry weight. The maximum value was observed in silver pomfret. Anchovy and silver pomfret with the highest content of petroleum hydrocarbons were known as good indicator for oil pollution in the studied area. From public health point of view, the detected concentrations for total petroleum hydrocarbons were lower than hazardous guidelines. The results were recorded as background data and information in the studied area; the continuous monitoring of pollutants is recommended, according to the rapid extension of industrial and oily activities in Hormozgan Province.

  16. New evidence suggests pyroclastic flows are responsible for the remarkable preservation of the Jehol biota

    Science.gov (United States)

    Jiang, Baoyu; Harlow, George E.; Wohletz, Kenneth; Zhou, Zhonghe; Meng, Jin

    2014-02-01

    The lower Cretaceous Yixian and Jiufotang formations contain numerous exceptionally well-preserved invertebrate, vertebrate and plant fossils that comprise the Jehol Biota. Freshwater and terrestrial fossils of the biota usually occur together within some horizons and have been interpreted as deposits of mass mortality events. The nature of the events and the mechanisms behind the exceptional preservation of the fossils, however, are poorly understood. Here, after examining and analysing sediments and residual fossils from several key horizons, we postulate that the causal events were mainly phreatomagmatic eruptions. Pyroclastic density currents were probably responsible for the major causalities and for transporting the bulk of the terrestrial vertebrates from different habitats, such as lizards, birds, non-avian dinosaurs and mammals, into lacustrine environments for burial. Terrestrial vertebrate carcasses transported by and sealed within the pyroclastic flows were clearly preserved as exceptional fossils through this process.

  17. Comparative uptake of uranium, thorium, and plutonium by biota inhabiting a contaminated Tennessee floodplain

    International Nuclear Information System (INIS)

    Garten, C.T. Jr.; Bondietti, E.A.; Walker, R.L.

    1981-01-01

    The uptake of 238 U, 232 Th, and 239 Pu from soil by fescue, grasshoppers, and small mammals was compared at the contaminated White Oak Creek floodplain in East Tennessee. Comparisons of actinide uptake were based on analyses of radionuclide ratios (U/Pu and Th/Pu) in soil and biota. U:Pu ratios in small mammal carcasses (shrews, mice, and rats) and bone samples from larger mammals (rabbit, woodchuck, opossum, and raccoon) were significantly greater (P less than or equal to 0.05) than U/Pu ratios in soil (based on 8M HNO 3 extractable). There was no significant difference between Th/Pu ratios in animals and soil. The order of actinide accumulation by biota from the site relative to contaminated soil was U > Th approx. = Pu

  18. A kinetic-allometric approach to predicting tissue radionuclide concentrations for biota

    Energy Technology Data Exchange (ETDEWEB)

    Higley, K. A.; Domotor, S. L.; Antonio, E. J.

    2003-01-01

    Allometry, or the biology of scaling, is the study of size and its consequences. It has become a useful tool for comparative phsiology. There are several allometric equations that relate body size to many parameters, including ingestion rate, lifespan, inhalation rate, home range and more. While these equations were originally derived from empirical observations, there is a growing body of evidence that these relationships have their origins in the dynamics of energy transport mechanisms. As part of an ongoing effort to assist the Department of Energy in developing generic methods for evaluating radiation dose to biota, we have examined the utility of applyig allometric techniques to predicting radionuclide tissue concentration across a large range of terrestrial and riparian species of animals. This particular study examined twenty-three elements. Initial investigations suggest that the allometric approach can provide a useful tool to derive limiting values of uptake and elimination factors for biota.

  19. MODEL INTERPOLASI GEOSTATISTIK LOGAM BERAT DAN BIOTA DI PERAIRAN MUARA SUNGAI KUIN

    Directory of Open Access Journals (Sweden)

    Abdur Rahman

    2016-10-01

    Full Text Available This study aimed to model the spatial content of heavy metals in water bodies and biota in the waters of the River Estuary Kuin. Data analysis methods are used to determine water quality status with spatial interpolation models Semivariogram (kriging and Inverse Distance weighting (IDW is integrated with  Geographic Information System (GIS. Based on calculations using the Ordinary Kriging method with Semivariogram/covariance modeling to model the heavy metals in water bodies Average Standard Error values average of 0.01641 (RMS = 0.01430 at the station Kuin River Estuary. Results of calculations using the Inverse Distance weighting method (IDW for models of heavy metals in biota obtained Root Mean Square value (RMS-error average of 0.29787 on Kuin River Estuary, and the mean value of the average station of 0.0138.

  20. Modelling of Biota Dose Effects. Report of Working Group 6 Biota Dose Effects Modelling of EMRAS II Topical Heading Reference Approaches for Biota Dose Assessment. Environmental Modelling for RAdiation Safety (EMRAS II) Programme

    International Nuclear Information System (INIS)

    2014-07-01

    Environmental assessment models are used for evaluating the radiological impact of actual and potential releases of radionuclides to the environment. They are essential tools for use in the regulatory control of routine discharges to the environment and in planning the measures to be taken in the event of accidental releases. They are also used for predicting the impact of releases which may occur far into the future, for example, from underground radioactive waste repositories. It is important to verify, to the extent possible, the reliability of the predictions of such models by a comparison with measured values in the environment or with the predictions of other models. The IAEA has been organizing programmes on international model testing since the 1980s. These programmes have contributed to a general improvement in models, in the transfer of data and in the capabilities of modellers in Member States. IAEA publications on this subject over the past three decades demonstrate the comprehensive nature of the programmes and record the associated advances which have been made. From 2009 to 2011, the IAEA organized a project entitled Environmental Modelling for RAdiation Safety (EMRAS II), which concentrated on the improvement of environmental transfer models and the development of reference approaches to estimate the radiological impacts on humans, as well as on flora and fauna, arising from radionuclides in the environment. Different aspects were addressed by nine working groups covering three themes: reference approaches for human dose assessment, reference approaches for biota dose assessment and approaches for addressing emergency situations. This publication describes the work of the Biota Effects Modelling Working Group

  1. Ciclagem de nutrientes via precipitação pluvial total, interna e escoamento pelo tronco em sistema agroflorestal com Gliricidia sepium Nutrient cycling through rainfall, throughfall and stemflow in an agroforestry system with Gliricidia sepium in semi-arid Paraiba, Brazil

    Directory of Open Access Journals (Sweden)

    Aldrin Martin Perez-Marin

    2008-12-01

    Full Text Available A deposição de nutrientes contidos na água de chuva que passa pela copa das árvores e que escoa pelo tronco até o solo pode constituir uma via importante da ciclagem biogeoquímica em sistemas agroflorestais de baixo uso de insumos externos. Todavia, não há informação disponível sobre esses processos em agroecossistemas da região semi-árida do Nordeste brasileiro. O presente trabalho foi conduzido em um sistema agroflorestal de cultivo em aléias, com gliricídia e milho, em Esperança, PB, e teve como objetivo quantificar: a proporção da água de chuva que escoa através da copa das árvores, ou pelo tronco, ou que é interceptada pela copa; e as entradas de N, P e K contidos na água escoada através da copa ou pelo tronco, bem como na água de chuva em áreas sem árvores. Na área experimental, foram delimitadas quatro parcelas, onde foram instalados coletores a 0,50 m de distância do tronco das árvores de gliricídia e coletores tipo ´colarinho´ acoplados ao redor do tronco destas. Paralelamente, foram instalados coletores em áreas adjacentes, sem árvores, para quantificação da precipitação pluvial total. Da precipitação pluvial total, 67 % escoou através da copa , 0,74 % escoou pelo tronco e 32 % foi interceptada pela copa das árvores. As concentrações de N e P foram similares nas amostras da água escoada através da copa ou pelo tronco, porém estas foram cerca de 300 % maiores do que na água de chuva. A concentração de K na água escoada pelo tronco foi cerca de 100 e 600 % maior do que na água escoada através da copa e na água de chuva, respectivamente. Em média, os aportes de N, P e K ao solo foram de 5, 1 e 24 kg ha-1 na água de chuva; 9, 2 e 62 kg ha-1 na água escoada através da copa; e 0,12, 0,02 e 1 kg ha-1 na água escoada pelo tronco, respectivamente. Os resultados demonstram a importância da adoção de sistemas agroflorestais para a sustentabilidade de sistemas agrícolas de baixo uso

  2. A Modelling Framework to Assess the Effect of Pressures on River Abiotic Habitat Conditions and Biota.

    Directory of Open Access Journals (Sweden)

    Jochem Kail

    Full Text Available River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a modelling framework was further developed and tested to assess the effect of pressures at different spatial scales on reach-scale habitat conditions and biota. Ecohydrological and 1D hydrodynamic models were used to predict discharge and water quality at the catchment scale and the resulting water level at the downstream end of a study reach. Long-term reach morphology was modelled using empirical regime equations, meander migration and 2D morphodynamic models. The respective flow and substrate conditions in the study reach were predicted using a 2D hydrodynamic model, and the suitability of these habitats was assessed with novel habitat models. In addition, dispersal models for fish and macroinvertebrates were developed to assess the re-colonization potential and to finally compare habitat suitability and the availability/ability of species to colonize these habitats. Applicability was tested and model performance was assessed by comparing observed and predicted conditions in the lowland Treene River in northern Germany. Technically, it was possible to link the different models, but future applications would benefit from the development of open source software for all modelling steps to enable fully automated model runs. Future research needs concern the physical modelling of long-term morphodynamics, feedback of biota (e.g., macrophytes on abiotic habitat conditions, species interactions, and empirical data on the hydraulic habitat suitability and dispersal abilities of macroinvertebrates. The modelling framework is flexible and allows for including additional models and investigating different research and management questions, e.g., in climate impact

  3. Methodology for estimating radiation dose rates to freshwater biota exposed to radionuclides in the environment

    International Nuclear Information System (INIS)

    Blaylock, B.G.; Frank, M.L.; O'Neal, B.R.

    1993-08-01

    The purpose of this report is to present a methodology for evaluating the potential for aquatic biota to incur effects from exposure to chronic low-level radiation in the environment. Aquatic organisms inhabiting an environment contaminated with radioactivity receive external radiation from radionuclides in water, sediment, and from other biota such as vegetation. Aquatic organisms receive internal radiation from radionuclides ingested via food and water and, in some cases, from radionuclides absorbed through the skin and respiratory organs. Dose rate equations, which have been developed previously, are presented for estimating the radiation dose rate to representative aquatic organisms from alpha, beta, and gamma irradiation from external and internal sources. Tables containing parameter values for calculating radiation doses from selected alpha, beta, and gamma emitters are presented in the appendix to facilitate dose rate calculations. The risk of detrimental effects to aquatic biota from radiation exposure is evaluated by comparing the calculated radiation dose rate to biota to the U.S. Department of Energy's (DOE's) recommended dose rate limit of 0.4 mGy h -1 (1 rad d -1 ). A dose rate no greater than 0.4 mGy h -1 to the most sensitive organisms should ensure the protection of populations of aquatic organisms. DOE's recommended dose rate is based on a number of published reviews on the effects of radiation on aquatic organisms that are summarized in the National Council on Radiation Protection and Measurements Report No. 109 (NCRP 1991). DOE recommends that if the results of radiological models or dosimetric measurements indicate that a radiation dose rate of 0. 1 mGy h -1 will be exceeded, then a more detailed evaluation of the potential ecological consequences of radiation exposure to endemic populations should be conducted

  4. Historical records of radioactive contamination in biota at the 200 Areas of the Hanford Site

    International Nuclear Information System (INIS)

    Johnson, A.R.; Markes, B.M.; Schmidt, J.W.; Shah, A.N.; Weiss, S.G.; Wilson, K.J.

    1994-06-01

    This document summarizes and reports a literature search of 85 environmental monitoring records of wildlife and vegetation (biota) at the 200 East Area and the 200 West Area of the Hanford Site since 1965. These records were published annually and provided the majority of the data in this report. Additional sources of data have included records of specific facilities, such as site characterization documents and preoperational environmental surveys. These documents have been released for public use. Records before 1965 were still being researched and therefore not included in this document. The intent of compiling these data into a single source was to identify past and current concentrations of radionuclides in biota at specific facilities and waste sites within each operable unit that may be used to help guide cleanup activities in the 200 Areas to be completed under the Comprehensive Environmental Response and Liability Act (CERCLA). The 200 East Area and 200 West Area were the locations of the Hanford Site separation and process facilities and waste management units. For the purposes of this document, a sample was of interest if a Geiger-Mueller counter equipped with a pancake probe-indicated beta/gamma emitting radioactivity above 200 counts per minute (cpm), or if laboratory radioanalyses indicated a radionuclide concentration equaled or exceeded 10 picocuries per gram (pCi/g). About 4,500 individual cases of monitoring for radionuclide uptake or transport in biota in the 200 Areas environs were included in the documents reviewed. About 1,900 (i.e., 42%) of these biota had radionuclide concentrations in excess of 10 pCi/g. These radionuclide transport or uptake cases were distributed among 45 species of wildlife (primarily small mammals and feces) and 30 species of vegetation. The wildlife species most commonly associated with radioactive contamination were the house mouse and the deer mouse and of vegetation species, the Russian thistle

  5. Methodology for estimating radiation dose rates to freshwater biota exposed to radionuclides in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G.; Frank, M.L.; O`Neal, B.R.

    1993-08-01

    The purpose of this report is to present a methodology for evaluating the potential for aquatic biota to incur effects from exposure to chronic low-level radiation in the environment. Aquatic organisms inhabiting an environment contaminated with radioactivity receive external radiation from radionuclides in water, sediment, and from other biota such as vegetation. Aquatic organisms receive internal radiation from radionuclides ingested via food and water and, in some cases, from radionuclides absorbed through the skin and respiratory organs. Dose rate equations, which have been developed previously, are presented for estimating the radiation dose rate to representative aquatic organisms from alpha, beta, and gamma irradiation from external and internal sources. Tables containing parameter values for calculating radiation doses from selected alpha, beta, and gamma emitters are presented in the appendix to facilitate dose rate calculations. The risk of detrimental effects to aquatic biota from radiation exposure is evaluated by comparing the calculated radiation dose rate to biota to the U.S. Department of Energy`s (DOE`s) recommended dose rate limit of 0.4 mGy h{sup {minus}1} (1 rad d{sup {minus}1}). A dose rate no greater than 0.4 mGy h{sup {minus}1} to the most sensitive organisms should ensure the protection of populations of aquatic organisms. DOE`s recommended dose rate is based on a number of published reviews on the effects of radiation on aquatic organisms that are summarized in the National Council on Radiation Protection and Measurements Report No. 109 (NCRP 1991). DOE recommends that if the results of radiological models or dosimetric measurements indicate that a radiation dose rate of 0. 1 mGy h{sup {minus}1} will be exceeded, then a more detailed evaluation of the potential ecological consequences of radiation exposure to endemic populations should be conducted.

  6. Accumulation of radionuclides in selected marine biota from Manjung coastal area

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, Anisa, E-mail: coppering@ymail.com; Hamzah, Zaini; Wood, Ab. Khalik [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Saat, Ahmad [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Alias, Masitah [TNB Reasearch Sdn. Bhd., Kawasan Institusi Penyelidikan, 43000 Kajang, Selangor (Malaysia)

    2015-04-29

    Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 ({sup 226}Ra), radium-228 ({sup 228}Ra) and potassium-40 ({sup 40}K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (H{sub in}), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption.

  7. TOXIC EFFECT OF PESTICIDES ON THE BIOTA OF FRESHWATER RESERVOIRS OF UKRAINE (A REVIEW)

    OpenAIRE

    N. Kolesnyk

    2015-01-01

    Purpose. To analyze scientific sources on the studies of toxic and lethal concentrations of pesticides on phytoplankton, zooplankton, zoobenthos and fish in current conditions of Ukraine. Findings. A review of works of a variety of scientists showed that pesticides with different chemical origins have disastrous effects on everyone without the exception of freshwater biota organisms. The article highlights the peculiarities of the toxic effects of pesticides of major chemical groups, whic...

  8. Mercury Accumulation in Biota of Tributaries of the Finger Lakes, New York

    Science.gov (United States)

    Cleckner, L.; Razavi, R.; Cushman, S. F.; Massey, T.

    2016-12-01

    Mercury (Hg) is an aquatic pollutant whose availability to a given waterbody is closely tied to watershed characteristics. Transport of Hg from watersheds to waterbodies is controlled primarily by dissolved organic carbon (DOC) and suspended particulate matter. This study was conducted to assess accumulation of Hg in biota of tributaries of five Finger Lakes watersheds in New York, USA. Very little is known regarding Hg dynamics within Finger Lakes stream food webs or how tributaries contribute to Hg transport to the lakes themselves. Sources of Hg in the region include atmospheric pollution from an active coal-fired power plant. Between May and October 2015, two species of stream fish (Blacknose Dace, Rhinichthys atratulus, and Creek Chub, Semotilus atromaculatus) were collected by backpack electrofishing. At the same time, benthic macroinvertebrates representing various feeding groups and periphyton were collected for methylmercury determination. Samples for suspended particulate matter, DOC, and specific ultraviolet absorbance were also collected. The study objectives were to determine 1) whether differences existed in fish biota Hg concentrations among lake watersheds, and 2) the influence of DOC and land use on observed biota Hg accumulation patterns. Preliminary analyses of fish Hg results indicate a difference in accumulation between the two indicator species selected. Mercury concentrations were found to increase with fish size. Across all lake watersheds, Creek Chub were found to be significantly larger than Blacknose Dace. However, there was no significant difference in Hg concentrations between the two species. A within watershed analysis of five Seneca Lake tributaries showed that average Hg concentrations were significantly higher in Blacknose Dace than Creek Chub. This suggests this species is more vulnerable to Hg accumulation and a better indicator of Hg availability. No significant differences were found in Creek Chub Hg concentrations among

  9. Accumulation of radionuclides in selected marine biota from Manjung coastal area

    International Nuclear Information System (INIS)

    Abdullah, Anisa; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad; Alias, Masitah

    2015-01-01

    Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 ( 226 Ra), radium-228 ( 228 Ra) and potassium-40 ( 40 K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (H in ), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption

  10. Concentrations and characteristics of organochlorine pesticides in aquatic biota from Qiantang River in China

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Rongbing [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)], E-mail: brz3000@163.com; Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)], E-mail: zlz@zju.edu.cn; Chen Yuyun; Kong Qingxia [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)

    2008-01-15

    The Qiantang River is a typical river flowing through an agricultural area in China. It was studied in 2006 for its aquatic biota quality by determining 13 organochlorine pesticides (OCPs) in the edible parts of crabs, clams, shrimp, fish, aquatic plants, as well as water and sediments collected from seven sites along its upper reaches all the way downstream. The levels of all insecticides were in the range of 17 {+-} 13 (water plants), 35 {+-} 36 (shrimp), 32 {+-} 14 (crabs), 39 {+-} 21 (clams), 47{+-}35 (fish) ng/g wet weight (ww) and in the range of 2936 {+-} 2356 (water plants), 5827 {+-} 6013 (shrimp), 2102 {+-} 966 (crabs), 1859 {+-} 1018 (clams), 3624 {+-} 11331 (fish) ng/g lipid. DDT and its metabolites were the predominant contaminants in most biota. A linear relationship was observed between the log bio-concentration factor (BCF) and log octanol-water partition coefficients (K{sub ow}) for fish, clams and shrimp. Composition analyses in various environmental media indicated a recent usage of lindane and dicofol into the river. - OCP residues still exist in aquatic biota from Qiantang River after the ban of OCPs twenty years ago.

  11. Evolution of Asian Interior Arid-Zone Biota: Evidence from the Diversification of Asian Zygophyllum (Zygophyllaceae)

    Science.gov (United States)

    Li, Hong-Lei; Yu, Sheng-Xiang; Zhang, Lin-Jing; Wang, Wei

    2015-01-01

    The Asian interior arid zone is the largest desert landform system in the Northern Hemisphere, and has high biodiversity. Little is currently known about the evolutionary history of its biota. In this study, we used Zygophyllum, an important and characteristic component of the Asian interior arid zone, to provide new insights into the evolution of this biota. By greatly enlarged taxon sampling, we present the phylogenetic analysis of Asian Zygophyllum based on two plastid and one nuclear markers. Our phylogenetic analyses indicate that Asian Zygophyllum and Sarcozygium form a clade and Sarcozygium is further embedded within the shrub subclade. An integration of phylogenetic, biogeographic, and molecular dating methods indicates that Zygophyllum successfully colonized the Asian interior from Africa in the early Oligocene, and Asian Zygophyllum became differentiated in the early Miocene and underwent a burst of diversification in the late Miocene associated with the expansion of Asian interior arid lands due to orogenetic and climatic changes. Combining diversification patterns of other important components of the Asian interior arid zone, we propose a multi-stage evolution model for this biota: the late Eocene–early Oligocene origin, the early Miocene expansion, and the middle-late Miocene rapid expansion to the whole Asian interior arid zone. This study also demonstrates that, for Zygophyllum and perhaps other arid-adapted organisms, arid biomes are evolutionary cradles of diversity. PMID:26393796

  12. Response of soil biota to vineyard interrow soil cultivation can be altered by the surrounding landscape

    Science.gov (United States)

    Zaller, Johann; Buchholz, Jacob; Querner, Pascal; Paredes, Daniel; Kratschmer, Sophie; Schwantzer, Martina; Winter, Silvia; Strauss, Peter; Bauer, Thomas; Burel, Françoise; Guernion, Muriel; Scimia, Jennifer; Nicolai, Annegret; Cluzeau, Daniel

    2017-04-01

    Ecosystem services provided by viticultural landscapes result from interactions between management intensity, soil properties, organisms inhabiting these landscapes, and the diversity and structure of the surrounding landscape. However, there is actually very little known to what extent these different factors influence the abundance and diversity of various soil biota. In this study we examined (i) to what extent different soil management intensities of interrows affect the activity and diversity of soil biota (earthworms, Collembola, litter decomposition), (ii) the role of soil properties in influencing these effects and (iii) whether the surrounding landscape structure is altering these interactions. We collected data in 16 vineyards in Austria embedded in landscapes with varying structure (i.e. from structurally simple to complex) and assessed earthworms (hand sorting), Collembola (pitfall trapping and soil coring), litter decomposition (tea bag method). Additionally, soil physical (water infiltration, aggregate stability, porosity, bulk density, soil texture) and chemical (pH, soil carbon content, cation exchange capacity, potassium, phosphorus) parameters were assessed. The landscape surrounding our vineyards within a radius of 750 m was assessed by field mapping using a geographical information system. Results showed that different soil biota/processes are differently affected by soil cultivation intensity and soil properties. Parameters describing the surrounding landscape interacted more with the responses of Collembola to soil cultivation than with earthworms or litter decomposition. These investigations are part of the transdisciplinary BiodivERsA project VineDivers (www.vinedivers.eu) and will ultimately lead into management recommendations for various stakeholders.

  13. Comparative analysis of doses to aquatic biota in water bodies impacted by radioactive contamination.

    Science.gov (United States)

    Kryshev, A I; Sazykina, T G

    2012-06-01

    Comparative analysis of doses to the reference species of freshwater biota was performed for the following water bodies in Russia or former USSR: Chernobyl NPPs cooling pond, Lakes Uruskul and Berdenish located in the Eastern Urals Radioactive Trace, Techa River, Yenisei River. It was concluded that the doses to biota were considerably different in the acute and chronic periods of radioactive contamination. The most vulnerable part of all considered aquatic ecosystems was benthic trophic chain. A numerical scale on the "dose rate - effects" relationships for fish was formulated. Threshold dose rates above which radiation effects can be expected in fish were evaluated to be the following: 1 mGy d(-1) for appearance of the first morbidity effects in fish; 5 mGy d(-1) for the first negative effects on reproduction system; 10 mGy d(-1) for the first effects on life shortening of fish. The results of dose assessment to biota were compared with the scale "dose rate - effects" and the literature data on the radiobiological effects observed in the considered water bodies. It was shown that in the most contaminated water bodies the dose rates were high enough to cause the radiobiological effects in fish. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. The biology and functional morphology of Macoma biota (Bivalvia: Tellinidae: Macominae

    Directory of Open Access Journals (Sweden)

    Pedro Ribeiro Piffer

    2011-06-01

    Full Text Available Macoma biota Arruda & Domaneschi, 2005, is a recently described species known only from the intertidal zone of Praia da Cidade, Caraguatatuba Bay, in the state of São Paulo, southeastern Brazil. The main purpose of the present paper is to describe the biology of M. biota, beginning with a detailed analysis of its anatomy and functional morphology and how these attributes are correlated with its habitat and life history. The morphology of the organs in the pallial cavity and their sorting devices indicate that this species has efficient mechanisms to process large amounts of particles that enter this cavity via the inhalant current. M. biota can rapidly select the material suitable for ingestion and direct the undesired excess to the rejection mantle tracts. These characteristics along with the siphon's behavior and the digestive tract configuration reveal that this species can be classified primarily as a deposit feeder, like other species of the genus; however, it can also behave as a suspension feeder, depending on the environmental conditions.

  15. Reviewing the serotonin reuptake inhibitors (SSRIs) footprint in the aquatic biota: Uptake, bioaccumulation and ecotoxicology

    International Nuclear Information System (INIS)

    a Comba, 3000-548 Coimbra (Portugal))" data-affiliation=" (REQUIMTE, Group of Bromatology, Pharmacognosy and Analytical Sciences, Faculty of Pharmacy, University of Coimbra, Polo III, Azinhaga de Sta Comba, 3000-548 Coimbra (Portugal))" >Silva, Liliana J.G.; a Comba, 3000-548 Coimbra (Portugal))" data-affiliation=" (REQUIMTE, Group of Bromatology, Pharmacognosy and Analytical Sciences, Faculty of Pharmacy, University of Coimbra, Polo III, Azinhaga de Sta Comba, 3000-548 Coimbra (Portugal))" >Pereira, André a Comba, 3000-548 Coimbra (Portugal))" data-affiliation=" (REQUIMTE, Group of Bromatology, Pharmacognosy and Analytical Sciences, Faculty of Pharmacy, University of Coimbra, Polo III, Azinhaga de Sta Comba, 3000-548 Coimbra (Portugal))" >M.P.T.; Meisel, Leonor M.; a Comba, 3000-548 Coimbra (Portugal))" data-affiliation=" (REQUIMTE, Group of Bromatology, Pharmacognosy and Analytical Sciences, Faculty of Pharmacy, University of Coimbra, Polo III, Azinhaga de Sta Comba, 3000-548 Coimbra (Portugal))" >Lino, Celeste M.; a Comba, 3000-548 Coimbra (Portugal))" data-affiliation=" (REQUIMTE, Group of Bromatology, Pharmacognosy and Analytical Sciences, Faculty of Pharmacy, University of Coimbra, Polo III, Azinhaga de Sta Comba, 3000-548 Coimbra (Portugal))" >Pena, Angelina

    2015-01-01

    Selective serotonin re-uptake inhibitors (SSRIs) antidepressants are amongst the most prescribed pharmaceutical active substances throughout the world. Their presence, already described in different environmental compartments such as wastewaters, surface, ground and drinking waters, and sediments, and their remarkable effects on non-target organisms justify the growing concern about these emerging environmental pollutants. A comprehensive review of the literature data with focus on their footprint in the aquatic biota, namely their uptake, bioaccumulation and both acute and chronic ecotoxicology is presented. Long-term multigenerational exposure studies, at environmental relevant concentrations and in mixtures of related compounds, such as oestrogenic endocrine disruptors, continue to be sparse and are imperative to better know their environmental impact. - Highlights: • Current knowledge of uptake and bioaccumulation of SSRIs. • Ecotoxicology and effects of SSRIs in the aquatic biota. • Identification of existing knowledge gaps. - A comprehensive review focussing SSRIs antidepressants footprint in the aquatic biota, namely their uptake, bioaccumulation, and both acute and chronic ecotoxicology is presented

  16. Non-human biota dose assessment. Sensitivity analysis and knowledge quality assessment

    International Nuclear Information System (INIS)

    Smith, K.; Robinson, C.; Jackson, D.; La Cruz, I. de; Zinger, I.; Avila, R.

    2010-10-01

    This report provides a summary of a programme of work, commissioned within the BIOPROTA collaborative forum, to assess the quantitative and qualitative elements of uncertainty associated with biota dose assessment of potential impacts of long-term releases from geological disposal facilities (GDF). Quantitative and qualitative aspects of uncertainty were determined through sensitivity and knowledge quality assessments, respectively. Both assessments focused on default assessment parameters within the ERICA assessment approach. The sensitivity analysis was conducted within the EIKOS sensitivity analysis software tool and was run in both generic and test case modes. The knowledge quality assessment involved development of a questionnaire around the ERICA assessment approach, which was distributed to a range of experts in the fields of non-human biota dose assessment and radioactive waste disposal assessments. Combined, these assessments enabled critical model features and parameters that are both sensitive (i.e. have a large influence on model output) and of low knowledge quality to be identified for each of the three test cases. The output of this project is intended to provide information on those parameters that may need to be considered in more detail for prospective site-specific biota dose assessments for GDFs. Such information should help users to enhance the quality of their assessments and build greater confidence in the results. (orig.)

  17. On the Origin of Pantepui montane biotas: A Perspective Based on the Phylogeny of Aulacorhynchus toucanets.

    Directory of Open Access Journals (Sweden)

    Elisa Bonaccorso

    Full Text Available To understand the origin of Pantepui montane biotas, we studied the biogeography of toucanets in the genus Aulacorhynchus. These birds are ideal for analyzing historical relationships among Neotropical montane regions, given their geographic distribution from Mexico south to Bolivia, including northern Venezuela (Cordillera de la Costa, and the Pantepui. Analyses were based on molecular phylogenies using mitochondrial and nuclear DNA sequences. Topology tests were applied to compare alternative hypotheses that may explain the current distribution of Aulacorhynchus toucanets, in the context of previous hypotheses of the origin of Pantepui montane biotas. Biogeographic reconstructions in RASP and Lagrange were used to estimate the ancestral area of the genus, and an analysis in BEAST was used to estimate a time framework for its diversification. A sister relationship between the Pantepui and Andes+Cordillera de la Costa was significantly more likely than topologies indicating other hypothesis for the origin of Pantepui populations. The Andes was inferred as the ancestral area for Aulacorhynchus, and the group has diversified since the late Miocene. The biogeographic patterns found herein, in which the Andes are the source for biotas of other regions, are consistent with those found for flowerpiercers and tanagers, and do not support the hypothesis of the geologically old Pantepui as a source of Neotropical montain diversity. Based on the high potential for cryptic speciation and isolation of Pantepui populations, we consider that phylogenetic studies of additional taxa are important from a conservation perspective.

  18. Comparison of passive sampling and biota for monitoring of tonalide in aquatic environment.

    Science.gov (United States)

    Tumova, Jitka; Grabicova, Katerina; Golovko, Oksana; Koba, Olga; Kodes, Vit; Fedorova, Ganna; Grabic, Roman; Kroupova, Hana Kocour

    2017-10-01

    Synthetic musk compounds are extensively used in personal care and cosmetic products all over the world. Afterwards, they are discharged into the environment mainly because they are not completely removed in wastewater treatment plants. The aim of this study was to investigate if a passive sampler is applicable for the monitoring of tonalide, a polycyclic musk compound, in the aquatic environment and to compare the levels of tonalide in pesticide-polar organic chemical integrative sampler (POCIS) and biota. For this purpose, four sampling localities on the three biggest rivers in the Czech Republic were selected. Tonalide was determined in POCIS at all sampling sites in the concentration ranging from 9 ng/POCIS (Labe River, Hradec Králové) to 25 ng/POCIS (Morava River, Blatec). The locality with the most frequent occurrence of tonalide in biota samples was the Morava River which well corresponded with the highest tonalide concentration in POCIS among sampling sites. The highest number of positive tonalide detections among all studied biota samples was found in fish plasma. To the best of our knowledge, this is the first evidence that tonalide bioaccumulates in fish blood. Tonalide levels were below the limit of quantification in benthos samples at all sampling sites.

  19. The Hunsrück biota: A unique window into the ecology of Lower Devonian arthropods.

    Science.gov (United States)

    Rust, Jes; Bergmann, Alexandra; Bartels, Christoph; Schoenemann, Brigitte; Sedlmeier, Stephanie; Kühl, Gabriele

    2016-03-01

    The approximately 400-million-year old Hunsrück biota provides a unique window into Devonian marine life. Fossil evidence suggests that this biota was dominated by echinoderms and various classes of arthropods, including Trilobita, stem lineage representatives of Euarthropoda, Chelicerata and Eucrustacea, as well as several crown group Chelicerata and Eucrustacea. The Hunsrück biota's exceptional preservation allows detailed reconstructions and description of key-aspects of its fauna's functional morphologies thereby revealing modes of locomotion, sensory perception, and feeding strategies. Morphological and stratigraphic data are used for a critical interpretation of the likely habitats, mode of life and nutritional characteristics of this diverse fauna. Potential predators include pycnogonids and other chelicerates, as well as the now extinct stem arthropods Schinderhannes bartelsi, Cambronatus brasseli and Wingertshellicus backesi. Mainly the deposit feeding Trilobita, Marrellomorpha and Megacheira, such as Bundenbachiellus giganteus, represents scavengers. Possibly, opportunistic scavenging was also performed by the afore-mentioned predators. Most of the studied arthropods appear to have been adapted to living in relatively well-illuminated conditions within the photic zone. Fossil evidence for associations amongst arthropods and other classes of metazoans is reported. These associations provide evidence of likely community structures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Biota dose assessment of small mammals sampled near uranium mines in northern Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Minter, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kuhne, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kubilius, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2018-01-09

    In 2015, the U. S. Geological Survey (USGS) collected approximately 50 small mammal carcasses from Northern Arizona uranium mines and other background locations. Based on the highest gross alpha results, 11 small mammal samples were selected for radioisotopic analyses. None of the background samples had significant gross alpha results. The 11 small mammals were identified relative to the three ‘indicator’ mines located south of Fredonia, AZ on the Kanab Plateau (Kanab North Mine, Pinenut Mine, and Arizona 1 Mine) (Figure 1-1) and are operated by Energy Fuels Resources Inc. (EFRI). EFRI annually reports soil analysis for uranium and radium-226 using Arizona Department of Environmental Quality (ADEQ)-approved Standard Operating Procedures for Soil Sampling (EFRI 2016a, 2016b, 2017). In combination with the USGS small mammal radioiosotopic tissue analyses, a biota dose assessment was completed by Savannah River National Laboratory (SRNL) using the RESidual RADioactivity-BIOTA (RESRAD-BIOTA, V. 1.8) dose assessment tool provided by the Argonne National Laboratory (ANL 2017).

  1. Megafauna moves nutrients uphill.

    Science.gov (United States)

    Gross, Michael

    2016-01-11

    Large animals have a disproportionate capacity to transport nutrients along gradients and against water flow directions, making them more available to ecosystems and ultimately saving them from disappearing in sea floor sediments. Megafauna extinctions have reduced this capacity dramatically, while humans and their livestock aren’t stepping in to restore this important ecosystem service.

  2. Biomonitoring aquatic pollution with feral eel (Anguilla anguilla): I. Bioaccumulation: biota-sediment ratios of PCBs, OCPs, PCDDs and PCDFs.

    NARCIS (Netherlands)

    van der Oost, R.; Opperhuizen, A.; Satumalay, K.; Heida, H.; Vermeulen, N.P.E.

    1996-01-01

    Samples of sediments and eel taken from six Amsterdam freshwater sites were analyzed for polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs). Biota-sediment accumulation factors (BSAFs) were

  3. The potentials of the third generation of flow injection analysis for nutrient monitoring and fractionation analysis

    DEFF Research Database (Denmark)

    Miró, Manuel; Hansen, Elo Harald; Buanuam, Janya

    2006-01-01

    In the present communication, the third generation of flow injection analysis, the so-called micro sequential-injection Laboratory-on-Valve (μSI-LOV), is presented as a miniaturized, automated approach for on-line monitoring of nutrients in different environmental compartments as effected under...... enclosed and strictly controlled conditions. Special emphasis is placed on coupling μSI-LOV on-line with a recently developed microcolumn to perform dynamic fractionation schemes for ascertaining the availability of phosphorous forms in solid substrates for biota uptake under simulated environmental...

  4. Life cycle responses of the midge Chironomus riparius to compounds with different modes of action

    NARCIS (Netherlands)

    Marinkovic, M.; Verweij, R.A.; Nummerdor, G.A.; Jonker, M.J.; Kraak, M.H.S.; Admiraal, W.

    2011-01-01

    Compounds with different modes of action may affect life cycles of biota differently. The aim of the present study was therefore to investigate the impact of four chemicals with different modes of action, including the essential metal copper, the nonessential metal cadmium, the organometal

  5. A simple biota removal algorithm for 35 GHz cloud radar measurements

    Science.gov (United States)

    Kalapureddy, Madhu Chandra R.; Sukanya, Patra; Das, Subrata K.; Deshpande, Sachin M.; Pandithurai, Govindan; Pazamany, Andrew L.; Ambuj K., Jha; Chakravarty, Kaustav; Kalekar, Prasad; Krishna Devisetty, Hari; Annam, Sreenivas

    2018-03-01

    Cloud radar reflectivity profiles can be an important measurement for the investigation of cloud vertical structure (CVS). However, extracting intended meteorological cloud content from the measurement often demands an effective technique or algorithm that can reduce error and observational uncertainties in the recorded data. In this work, a technique is proposed to identify and separate cloud and non-hydrometeor echoes using the radar Doppler spectral moments profile measurements. The point and volume target-based theoretical radar sensitivity curves are used for removing the receiver noise floor and identified radar echoes are scrutinized according to the signal decorrelation period. Here, it is hypothesized that cloud echoes are observed to be temporally more coherent and homogenous and have a longer correlation period than biota. That can be checked statistically using ˜ 4 s sliding mean and standard deviation value of reflectivity profiles. The above step helps in screen out clouds critically by filtering out the biota. The final important step strives for the retrieval of cloud height. The proposed algorithm potentially identifies cloud height solely through the systematic characterization of Z variability using the local atmospheric vertical structure knowledge besides to the theoretical, statistical and echo tracing tools. Thus, characterization of high-resolution cloud radar reflectivity profile measurements has been done with the theoretical echo sensitivity curves and observed echo statistics for the true cloud height tracking (TEST). TEST showed superior performance in screening out clouds and filtering out isolated insects. TEST constrained with polarimetric measurements was found to be more promising under high-density biota whereas TEST combined with linear depolarization ratio and spectral width perform potentially to filter out biota within the highly turbulent shallow cumulus clouds in the convective boundary layer (CBL). This TEST technique is

  6. Environmental Setting and the Effects of Natural and Human-Related Factors on Water Quality and Aquatic Biota, Oahu, Hawaii

    Science.gov (United States)

    Oki, Delwyn S.; Brasher, Anne M.D.

    2003-01-01

    -use patterns on Oahu reflected increases in population and decreases in large-scale agricultural operations over time. The last two remaining sugarcane plantations on Oahu closed in the mid-1990's, and much of the land that once was used for sugarcane now is urbanized or used for diversified agriculture. Although two large pineapple plantations continue to operate in central Oahu, some of the land previously used for pineapple cultivation has been urbanized. Natural and human-related factors control surface- and ground-water quality and the distribution and abundance of aquatic biota on Oahu. Natural factors that may affect water quality include geology, soils, vegetation, rainfall, ocean-water quality, and air quality. Human-related factors associated with urban and agricultural land uses also may affect water quality. Ground-water withdrawals may cause saltwater intrusion. Pesticides and fertilizers that were used in agricultural or urban areas have been detected in surface and ground water on Oahu. In addition, other organic compounds associated with urban uses of chemicals have been detected in surface and ground water on Oahu. The effects of urbanization and agricultural practices on instream and riparian areas in conjunction with a proliferation of nonnative fish and crustaceans have resulted in a paucity of native freshwater macrofauna on Oahu. A variety of pesticides, nutrients, and metals are associated with urban and agricultural land uses, and these constituents can affect the fish and invertebrates that live in the streams.

  7. Late gestational nutrient restriction

    DEFF Research Database (Denmark)

    Tygesen, Malin Plumhoff; Nielsen, Mette Olaf; Nørgaard, Peder

    2008-01-01

    We investigated the effect of 50% nutrient restriction during the last 6 weeks of gestation on twin-pregnant ewes' plasma glucose, non-esterified fatty acid, ß-hydroxybutyrate, insulin, IGF-1 and leptin concentrations and the effects on lamb birth weight and ewes' lactation performance. Plasma...... metabolite and hormone concentrations in restricted ewes suggest that maternal tissues were being mobilised. Despite the ewes' adaptations their lambs weighed significantly less at birth. Furthermore, colostrum and milk yields were markedly reduced up until the latest measurement at 3 weeks post partum...... despite adlibitum access to feed. Reduced milk yields coincided with reduced plasma IGF-1 concentration pre partum in nutrient restricted ewes indicating, that mammary gland development may have been compromised. The present data suggest that leptin is not involved in the regulation of early lactation...

  8. Nutrients in the nexus

    Science.gov (United States)

    Davidson, Eric A.; Niphong, Rachel; Ferguson, Richard B.; Palm, Cheryl; Osmond, Deanna L.; Baron, Jill S.

    2016-01-01

    Synthetic nitrogen (N) fertilizer has enabled modern agriculture to greatly improve human nutrition during the twentieth century, but it has also created unintended human health and environmental pollution challenges for the twenty-first century. Averaged globally, about half of the fertilizer-N applied to farms is removed with the crops, while the other half remains in the soil or is lost from farmers’ fields, resulting in water and air pollution. As human population continues to grow and food security improves in the developing world, the dual development goals of producing more nutritious food with low pollution will require both technological and socio-economic innovations in agriculture. Two case studies presented here, one in sub-Saharan Africa and the other in Midwestern United States, demonstrate how management of nutrients, water, and energy is inextricably linked in both small-scale and large-scale food production, and that science-based solutions to improve the efficiency of nutrient use can optimize food production while minimizing pollution. To achieve the needed large increases in nutrient use efficiency, however, technological developments must be accompanied by policies that recognize the complex economic and social factors affecting farmer decision-making and national policy priorities. Farmers need access to affordable nutrient supplies and support information, and the costs of improving efficiencies and avoiding pollution may need to be shared by society through innovative policies. Success will require interdisciplinary partnerships across public and private sectors, including farmers, private sector crop advisors, commodity supply chains, government agencies, university research and extension, and consumers.

  9. Bone nutrients for vegetarians.

    Science.gov (United States)

    Mangels, Ann Reed

    2014-07-01

    The process of bone mineralization and resorption is complex and is affected by numerous factors, including dietary constituents. Although some dietary factors involved in bone health, such as calcium and vitamin D, are typically associated with dairy products, plant-based sources of these nutrients also supply other key nutrients involved in bone maintenance. Some research suggests that vegetarian diets, especially vegan diets, are associated with lower bone mineral density (BMD), but this does not appear to be clinically significant. Vegan diets are not associated with an increased fracture risk if calcium intake is adequate. Dietary factors in plant-based diets that support the development and maintenance of bone mass include calcium, vitamin D, protein, potassium, and soy isoflavones. Other factors present in plant-based diets such as oxalic acid and phytic acid can potentially interfere with absorption and retention of calcium and thereby have a negative effect on BMD. Impaired vitamin B-12 status also negatively affects BMD. The role of protein in calcium balance is multifaceted. Overall, calcium and protein intakes in accord with Dietary Reference Intakes are recommended for vegetarians, including vegans. Fortified foods are often helpful in meeting recommendations for calcium and vitamin D. Plant-based diets can provide adequate amounts of key nutrients for bone health. © 2014 American Society for Nutrition.

  10. Trends in nutrients

    Science.gov (United States)

    Heathwaite, A.L.; Johnes, P.J.; Peters, N.E.

    1996-01-01

    The roles of nitrogen (N) and phosphorus (P) as key nutrients determining the trophic status of water bodies are examined, and evidence reviewed for trends in concentrations of N and P species which occur in freshwaters, primarily in northern temperate environments. Data are reported for water bodies undergoing eutrophication and acidification, especially water bodies receiving increased nitrogen inputs through the atmospheric deposition of nitrogen oxides (NOx). Nutrient loading on groundwaters and surface freshwaters is assessed with respect to causes and rates of (change, relative rates of change for N and P, and implications of change for the future management of lakes, rivers and groundwaters. In particular, the nature and emphasis of studies for N species and P fractions in lakes versus rivers and groundwaters are contrasted. This review paper primarily focuses on results from North America and Europe, particularly for the UK where a wide range of data sets exists. Few nutrient loading data have been published on water bodies in less developed countries; however, some of the available data are presented to provide a global perspective. In general, N and P concentrations have increased dramatically (>20 times background concentrations) in many areas and causes vary considerably, ranging from urbanization to changes in agricultural practices.

  11. Natural Radioactivity in Biota From Balok River and Its Associated Committed Effective Dose to Human

    International Nuclear Information System (INIS)

    Mei-Wo, Y.; Zal Uyun Wan Mahmood; Mohamad Noh Sawon; Khairul Nizam Razali; Dainee Nor Fardzilla Ahmad Tugi

    2016-01-01

    Several types of biota samples such as fishes, crabs and snails were collected from the Balok river which located close to the Gebeng industrial site that situated Lynas rare earth processing plant. Local communities were worried that operational of Lynas plant could introduce some radioactive contaminants into the adjacent river and endanger the aquatic animals and people. The activity concentration of radionuclides in these biota samples were determined using HPGe Gamma spectrometry system and found to be low and insignificant. They were ranged from MDA (Minimum Detectable Activity) to 2.88 Bq/ kg, MDA to 6.75 Bq/ kg, MDA to 7.98 Bq/ kg, MDA to 4.43 Bq/ kg and MDA to 32.50 Bq/ kg, for 226 Ra, 228 Ra, 238 U, 232 Th and 40 K, respectively. The MDA values for these radionuclides were varies and quiet high due to the limited sample size available. Using the computer code ERICA tool, it was found that the radiation risk of these radionuclides to the aquatic lives to be less than 1 μGy/ h and was below than the probability selected and therefore the potential radiation risk to human being should also be low. By using the dose conversion factors given in the AELB (Basic Safety Radiation Protection) Regulation 2010, assuming an adult consumed one kilogram of these contaminated biota, he would expected to receive a total committed effective dose per unit intake between 2.2 - 23.7 μSv depending on the consumed species. However, this value was far below the annual dose limit of 1,000 μSv for general public as stipulated under Act 304. (author)

  12. Cretaceous biota of the Triângulo Mineiro region (Brazil: A review of recent finds

    Directory of Open Access Journals (Sweden)

    Candeiro, C. R. A.

    2007-06-01

    Full Text Available The Bauru Group (Adamantina, Uberaba, and Marília Formations crop out in the Triângulo Mineiro region, Minas Gerais State, Brazil, and yield a rich continental biota. Invertebrate and vertebrate taxa from underlying and overlying strata, as well as biostratigraphical correlations with other fossil sites in Argentina, suggest an Upper Cretaceous age for this biota. The diversity of the fossil assemblage recorded in these formations is summarized here and includes: frogs, lizards, crocodiles, titanosaurs, abelisaurid and carcharodontosaurid dinosaurs. This fossil assemblage provides important clues to understand faunas from other southern landmasses, particularly those from the Cretaceous of the African continent.Los afloramientos del Grupo Bauru (formaciones Adamantina, Uberaba y Marília en la región del Triângulo Mineiro, Provincia de Minas Gerais, Brasil, posee un rico contenido de biota continental. Los taxa de invertebrados y vertebrados de estos estratos, así como las correlaciones biostratigráficas con otros yacimientos fósiles de Argentina, sugieren una edad del Cretácico Tardío. La diversidad de la asociación fósil registrada en las formaciones del Triângulo Mineiro se resume en el presente trabajo e incluye: sapos, lagartos, tortugas, cocodrilianos, titanosaurideos, dinosaurios abelisaurideos y carcharodontosaurideos. Esta asociación es importante para la comprensión de las faunas del sur de América y también de las del Cretácico de África.

  13. Including spatial data in nutrient balance modelling on dairy farms

    Science.gov (United States)

    van Leeuwen, Maricke; van Middelaar, Corina; Stoof, Cathelijne; Oenema, Jouke; Stoorvogel, Jetse; de Boer, Imke

    2017-04-01

    The Annual Nutrient Cycle Assessment (ANCA) calculates the nitrogen (N) and phosphorus (P) balance at a dairy farm, while taking into account the subsequent nutrient cycles of the herd, manure, soil and crop components. Since January 2016, Dutch dairy farmers are required to use ANCA in order to increase understanding of nutrient flows and to minimize nutrient losses to the environment. A nutrient balance calculates the difference between nutrient inputs and outputs. Nutrients enter the farm via purchased feed, fertilizers, deposition and fixation by legumes (nitrogen), and leave the farm via milk, livestock, manure, and roughages. A positive balance indicates to which extent N and/or P are lost to the environment via gaseous emissions (N), leaching, run-off and accumulation in soil. A negative balance indicates that N and/or P are depleted from soil. ANCA was designed to calculate average nutrient flows on farm level (for the herd, manure, soil and crop components). ANCA was not designed to perform calculations of nutrient flows at the field level, as it uses averaged nutrient inputs and outputs across all fields, and it does not include field specific soil characteristics. Land management decisions, however, such as the level of N and P application, are typically taken at the field level given the specific crop and soil characteristics. Therefore the information that ANCA provides is likely not sufficient to support farmers' decisions on land management to minimize nutrient losses to the environment. This is particularly a problem when land management and soils vary between fields. For an accurate estimate of nutrient flows in a given farming system that can be used to optimize land management, the spatial scale of nutrient inputs and outputs (and thus the effect of land management and soil variation) could be essential. Our aim was to determine the effect of the spatial scale of nutrient inputs and outputs on modelled nutrient flows and nutrient use efficiencies

  14. Soil fertility in deserts: a review on the influence of biological soil crusts and the effect of soil surface disturbance on nutrient inputs and losses

    Science.gov (United States)

    Reynolds, R.; Phillips, S.; Duniway, M.; Belnap, J.

    2003-01-01

    Sources of desert soil fertility include parent material weathering, aeolian deposition, and on-site C and N biotic fixation. While parent materials provide many soil nutrients, aeolian deposition can provide up to 75% of plant-essential nutrients including N, P, K, Mg, Na, Mn, Cu, and Fe. Soil surface biota are often sticky, and help retain wind-deposited nutrients, as well as providing much of the N inputs. Carbon inputs are from both plants and soil surface biota. Most desert soils are protected by cyanobacterial-lichen-moss soil crusts, chemical crusts and/or desert pavement. Experimental disturbances applied in US deserts show disruption of soil surfaces result in decreased N and C inputs from soil biota by up to 100%. The ability to glue aeolian deposits in place is compromised, and underlying soils are exposed to erosion. The ability to withstand wind increases with biological and physical soil crust development. While most undisturbed sites show little sediment production, disturbance by vehicles or livestock produce up to 36 times more sediment production, with soil movement initiated at wind velocities well below commonly-occurring wind speeds. Soil fines and flora are often concentrated in the top 3 mm of the soil surface. Winds across disturbed areas can quickly remove this material from the soil surface, thereby potentially removing much of current and future soil fertility. Thus, disturbances of desert soil surfaces can both reduce fertility inputs and accelerate fertility losses.

  15. A brief history of sea ice biota studies at Syowa Station and its vicinity (review)

    OpenAIRE

    Hoshiai,Takao; Watanabe,Kentaro

    1996-01-01

    A history of sea ice biota studies which were carried out at Syowa Station (69°00′S, 39°35′E) and its vicinity is outlined. The process of the surface community formation in ice floes, the bimodal proliferation of ice algae in the bottom layer of fast ice and the algae-copepod-fish link associated with fast ice were mainly investigated. Based on the results obtained from the Syowa Station area and those from other locations, the distribution of ice algal communities, the seasonality in format...

  16. Behaviour of molluscs in cantabrian biota with respect to the activity present in the marine medium

    International Nuclear Information System (INIS)

    Montesinos, M.; Santos, A.M. de los

    1981-01-01

    The behaviour of molluscs with regard to the activity present in the marine medium is studied. For this purpose three large groups are considered, with special reference to their ecology and their particular mode of incorporating activity. Determinations are made of the total alpha and beta activity, as well as that due to elements such as 90 Sr, 137 Cs and natural U, in the organisms in question and in their eco-environment. A comparison is likewise established between the biocoenoses inhabiting Cantabrian and Mediterranean biota. (author)

  17. IOLOGICAL IMPORTANCE AND TOXICITY OF HEAVY METALS FOR BIOTA OF FRESHWATER BODIES (REVIEW)

    OpenAIRE

    I. Hrytsyniak; N. Kolesnyk

    2014-01-01

    Purpose. To investigate the sources of scientific information on biological functions of heavy metals (Fe, Zn, Mn, Cu, Ni, Co, Pb, Cd) and their negative effect on biota of fresh water bodies. Findings. A review of works of a variety of scientists showed that the majority of the studied heavy metals (Fe, Zn, Mn, Cum and Co) played an important role in vital functions of freshwater organisms. The significance of other studied heavy metals (Ni, Pb, and Cd) is probable or unknown. Besides bi...

  18. Radioactive contamination of the environment and biota on Novaya Zemlya following nuclear weapon tests

    International Nuclear Information System (INIS)

    Matishov, G.G.; Matishov, D.G.; Shchipa, E.; Pavlova, L.G.

    1994-01-01

    Data of radiochemical studies have shown that in key elements of ecosystems on the archipelago (lake and sea waters, bottom deposits, mosses lichens, birds and deer) the content of Cs 137 and other radioisotopes is within the background level. Bottom deposits and soils of local territories of the abandoned nuclear test sites are the exception (the concentration of radioisotopes in the environment and biota amounts to 5000 Bq/rg and more). It is recommended that mosses and lichens on the ground and benthonic organisms in the sea should be used as biological indicators of artificial radiological background

  19. Aggregated filter-feeding consumers alter nutrient limitation: consequences for ecosystem and community dynamics.

    Science.gov (United States)

    Atkinson, Carla L; Vaughn, Caryn C; Forshay, Kenneth J; Cooper, Joshua T

    2013-06-01

    Nutrient cycling is a key process linking organisms in ecosystems. This is especially apparent in stream environments in which nutrients are taken up readily and cycled through the system in a downstream trajectory. Ecological stoichiometry predicts that biogeochemical cycles of different elements are interdependent because the organisms that drive these cycles require fixed ratios of nutrients. There is growing recognition that animals play an important role in biogeochemical cycling across ecosystems. In particular, dense aggregations of consumers can create biogeochemical hotspots in aquatic ecosystems via nutrient translocation. We predicted that filter-feeding freshwater mussels, which occur as speciose, high-biomass aggregates, would create biogeochemical hotspots in streams by altering nutrient limitation and algal dynamics. In a field study, we manipulated nitrogen and phosphorus using nutrient-diffusing substrates in areas with high and low mussel abundance, recorded algal growth and community composition, and determined in situ mussel excretion stoichiometry at 18 sites in three rivers (Kiamichi, Little, and Mountain Fork Rivers, south-central United States). Our results indicate that mussels greatly influence ecosystem processes by modifying the nutrients that limit primary productivity. Sites without mussels were N-limited with -26% higher relative abundances of N-fixing blue-green algae, while sites with high mussel densities were co-limited (N and P) and dominated by diatoms. These results corroborated the results of our excretion experiments; our path analysis indicated that mussel excretion has a strong influence on stream water column N:P. Due to the high N:P of mussel excretion, strict N-limitation was alleviated, and the system switched to being co-limited by both N and P. This shows that translocation of nutrients by mussel aggregations is important to nutrient dynamics and algal species composition in these rivers. Our study highlights the

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

    Science.gov (United States)

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

    2014-01-01

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

  1. 9 Nutrient Load of the Sakumo Lagoon.cdr

    African Journals Online (AJOL)

    Administrator

    cycles of marine fish and prawn species, as well as fisheries further ... Pollution of the lagoon with nutrients can affect biodiversity of plant and animal species, especially water fowls and birds ecology, since the site is noted for its large number of birds (Ntiamoa- ... found along most of the river courses within the Ramsar site.

  2. Applying DoE's Graded Approach for assessing radiation impacts to non-human biota at the Incl

    International Nuclear Information System (INIS)

    Morris, Randall C.

    2006-01-01

    In July 2002, The US Department of Energy (DOE) released a new technical standard entitled A Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota. DOE facilities are annually required to demonstrate that routine radioactive releases from their sites are protective of non-human receptors and sites are encouraged to use the Graded Approach for this purpose. Use of the Graded Approach requires completion of several preliminary steps, to evaluate the degree to which the site environmental monitoring program is appropriate for evaluating impacts to non-human biota. We completed these necessary activities at the Idaho National Laboratory (INL) using the following four tasks: (1) develop conceptual models and evaluate exposure pathways; (2) define INL evaluation areas; (3) evaluate sampling locations and media; (4) evaluate data gaps. All of the information developed in the four steps was incorporated, data sources were identified, departures from the Graded Approach were justified, and a step-by-step procedure for biota dose assessment at the INL was specified. Finally, we completed a site-wide biota dose assessment using the 2002 environmental surveillance data and an offsite assessment using soil and surface water data collected since 1996. These assessments demonstrated the environmental concentrations of radionuclides measured on and near the INL do not present significant risks to populations of non-human biota

  3. Stoichiometric patterns in foliar nutrient resorption across multiple scales

    Science.gov (United States)

    Reed, Sasha C.; Townsend, Alan R.; Davidson, Eric A.; Cleveland, Cory C.

    2012-01-01

    *Nutrient resorption is a fundamental process through which plants withdraw nutrients from leaves before abscission. Nutrient resorption patterns have the potential to reflect gradients in plant nutrient limitation and to affect a suite of terrestrial ecosystem functions. *Here, we used a stoichiometric approach to assess patterns in foliar resorption at a variety of scales, specifically exploring how N : P resorption ratios relate to presumed variation in N and/or P limitation and possible relationships between N : P resorption ratios and soil nutrient availability. *N : P resorption ratios varied significantly at the global scale, increasing with latitude and decreasing with mean annual temperature and precipitation. In general, tropical sites (absolute latitudes age along an Amazonian forest regeneration chronosequence and among species in a diverse Costa Rican rain forest. *These results suggest that variations in N : P resorption stoichiometry offer insight into nutrient cycling and limitation at a variety of spatial scales, complementing other metrics of plant nutrient biogeochemistry. The extent to which the stoichiometric flexibility of resorption will help regulate terrestrial responses to global change merits further investigation.

  4. Dopamine alleviates nutrient deficiency-induced stress in Malus hupehensis.

    Science.gov (United States)

    Liang, Bowen; Li, Cuiying; Ma, Changqing; Wei, Zhiwei; Wang, Qian; Huang, Dong; Chen, Qi; Li, Chao; Ma, Fengwang

    2017-10-01

    Dopamine mediates many physiological processes in plants. We investigated its role in regulating growth, root system architecture, nutrient uptake, and responses to nutrient deficiencies in Malus hupehensis Rehd. Under a nutrient deficiency, plants showed significant reductions in growth, chlorophyll concentrations, and net photosynthesis, along with disruptions in nutrient uptake, transport, and distribution. However, pretreatment with 100 μM dopamine markedly alleviated such inhibitions. Supplementation with that compound enabled plants to maintain their photosynthetic capacity and development of the root system while promoting the uptake of N, P, K, Ca, Mg, Fe, Mn, Cu, Zn, and B, altering the way in which those nutrients were partitioned throughout the plant. The addition of dopamine up-regulated genes for antioxidant enzymes involved in the ascorbate-glutathione cycle (MdcAPX, MdcGR, MdMDHAR, MdDHAR-1, and MdDHAR-2) but down-regulated genes for senescence (SAG12, PAO, and MdHXK). These results indicate that exogenous dopamine has an important antioxidant and anti-senescence effect that might be helpful for improving nutrient uptake. Our findings demonstrate that dopamine offers new opportunities for its use in agriculture, especially when addressing the problem of nutrient deficiencies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Carbon footprint of urban source separation for nutrient recovery.

    Science.gov (United States)

    Kjerstadius, H; Bernstad Saraiva, A; Spångberg, J; Davidsson, Å

    2017-07-15

    Source separation systems for the management of domestic wastewater and food waste has been suggested as more sustainable sanitation systems for urban areas. The present study used an attributional life cycle assessment to investigate the carbon footprint and potential for nutrient recovery of two sanitation systems for a hypothetical urban area in Southern Sweden. The systems represented a typical Swedish conventional system and a possible source separation system with increased nutrient recovery. The assessment included the management chain from household collection, transport, treatment and final return of nutrients to agriculture or disposal of the residuals. The results for carbon footprint and nutrient recovery (phosphorus and nitrogen) concluded that the source separation system could increase nutrient recovery (0.30-0.38 kg P capita -1 year -1 and 3.10-3.28 kg N capita -1 year -1 ), while decreasing the carbon footprint (-24 to -58 kg CO 2 -eq. capita -1 year -1 ), compared to the conventional system. The nutrient recovery was increased by the use of struvite precipitation and ammonium stripping at the wastewater treatment plant. The carbon footprint decreased, mainly due to the increased biogas production, increased replacement of mineral fertilizer in agriculture and less emissions of nitrous oxide from wastewater treatment. In conclusion, the study showed that source separation systems could potentially be used to increase nutrient recovery from urban areas, while decreasing the climate impact. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Nutrient losses from Fall and Winter-applied manure: Effects of timing and soil temperature

    Science.gov (United States)

    Soil temperature is a major environmental factor that affects both the infiltration of meltwater and precipitation, and nutrient cycling. The objectives of this study were to determine nutrient losses in runoff and leachate from fall and winter-applied dairy manure based on the soil temperature at t...

  7. Nutrient inputs to the coastal ocean through submarine groundwater discharge: controls and potential impact

    NARCIS (Netherlands)

    Slomp, C.P.; Van Cappellen, P.

    2004-01-01

    Nutrient input through submarine groundwater discharge (SGD) rivals river inputs in certain regions and may play a significant role in nutrient cycling and primary productivity in the coastal ocean. In this paper, we review the key factors determining the fluxes of nitrogen (N) and phosphorus (P)

  8. Spatial distribution of radionuclides in Lake Michigan biota near the Big Rock Point Nuclear Plant

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Yaguchi, E.M.; Nelson, D.M.; Marshall, J.S.

    1974-01-01

    A survey was made of four groups of biota in the vicinity of the Big Rock Point Nuclear Plant near Charlevoix, Michigan, to determine their usefulness in locating possible sources of plutonium and other radionuclides to Lake Michigan. This 70 MW boiling-water reactor, located on the Lake Michigan shoreline, was chosen because its fuel contains recycled plutonium, and because it routinely discharges very low-level radioactive wastes into the lake. Samples of crayfish (Orconectes sp.), green algae (Chara sp. and Cladophora sp.), and an aquatic macrophyte (Potamogeton sp.) were collected in August 1973, at varying distances from the discharge and analyzed for 239 240 Pu, 90 Sr, and five gamma-emitting radionuclides. Comparison samples of reactor waste solution have also been analyzed for these radionuclides. Comparisons of the spatial distributions of the extremely low radionuclide concentrations in biota clearly indicated that 137 Cs, 134 Cs, 65 Zn, and 60 Co were released from the reactor; their concentrations decreased exponentially with increasing distance from the discharge. Conversely, concentrations of 239 240 Pu, 95 Zr, and 90 Sr showed no correlation with distance, suggesting any input from Big Rock was insignificant with respect to the atmospheric origin of these isotopes. The significance of these results is discussed, particularly with respect to current public debate over the possibility of local environmental hazards associated with the use of plutonium as a nuclear fuel. (U.S.)

  9. The role of soil biota in the weathering of minerals: A review of literature

    Science.gov (United States)

    Sokolova, T. A.

    2011-01-01

    Two methodological approaches used in the study of the mineral weathering in soils under the effect of biota were analyzed. According to one approach, which is based on the concepts of coordination chemistry, the dissolution of minerals is considered at the ion-molecule level and can be described using the terms and notions of classical thermodynamics. According to the other approach, the weathering of minerals in the supergenesis zone is considered at the ion-electron level within the framework of the corrosion model of supergenesis on the basis of anode-cathode processes, when the mineral in the electrolyte environment serves as an anode and is oxidized being an electron donor. Microorganisms act as a cathodic associate of minerals, i.e., an electron acceptor. The kinetic parameters related to the rate of the biological processes and the diffusion come out on top in this case. The review deals with the mechanisms of the direct and indirect effect of biota on the weathering of minerals in soils; the features of the soil in the rhizosphere and the ectomycorrhizosphere; the impact of fungi, bacteria, and higher plants on the minerals; and the generated synergistic effect.

  10. PENGGUNAAN EKSTRAK BIOTA LAUTAGLAOPHENIA SP. UNTUK MENGENDALIKANFUSARIUM OXYSPORUM F.SP.VANILLAE PENYEBAB BUSUK BATANG VANILI

    Directory of Open Access Journals (Sweden)

    I KETUT SUADA

    2012-11-01

    Full Text Available The Use of Aglaophenia sp. Marine Biota Extract to Control Fusarium oxysporum f. sp. vanillae, a Pathogen of Vanilla Stem Rot The use of marine biota for organic fungicide material has enormous potential to be developed. The organic fungicide was directed to substitute synthetic fungicide for vanilla cultivation. Application of synthetic fungicide degraded environmental quality, therefore its applications does not support sustainable agriculture. The objective of this research was to know the potence of Aglaopheniain suppressing the growth of F. oxysporum f. sp.vanillae, the pathogen of vanilla stem rot. The research was done in green house in order to find the best substance for formulation of the extract. The substances screened were water, tween-80, and detergents with two different concentrations. Subsequently, two best formulas were chosen to apply in endemic area in Tabanan. The green house and field trial research used Randomized Completely Design with three and five replications respectively. Results showed that tween was the best substance used for formulation and concentration of 0.2% was better than other concentrations. The extract diluted in tween-80 on the concentration of 0.2% showed the lowest rot on stem, longest shoot, and the most leaves on vanilla shoot. Because of its significant performance, the 0.1% extract ofAglaopheniain 0.1% tween-80 was proposed to be the best formula to suppress the vanilla stem rot disease.

  11. Study of the behaviour of transuranics and possible chemical homologues in Lake Michigan water and biota

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Alberts, J.J.; Nelson, D.M.; Orlandini, K.A.

    1976-01-01

    Concentration factors for Pu, Am and U in Lake Michigan biota are compared to those of a number of stable trace elements that have short residence times in Lake Michigan water. The relative order of uptake for these nuclides in Lake Michigan biota is Am>Pu much>U. Evidence is summarized which suggests that the predominant oxidation state of 239 , 240 Pu in Lake Michigan water is 4+. Concentrations of 239 , 240 Pu in net plankton, filterable particulate matter, sediment trap, and benthic floc samples indicate that sorption by biogenic detritus, and settling of this material, can account for the reduced concentration of 239 , 240 Pu observed in surface waters during summer stratification, but that deposition into the sediments is primarily non-biological. Concentrations of 7 Be, 144 Ce and 137 Cs in sediment trap samples show the effect of spring convective mixing and demonstrate the resuspension of mineral-rich surficial sediments during the summer months. The effect on the concentration of dissolved plutonium in the water column, of varying degrees of resuspension of sedimentary floc, is described using a simple mass-action model. A radiochemical method for the determination of americium and uranium in Lake Michigan environmental samples is also presented. (author)

  12. Heavy metals in seawater, sediments, and biota from the coastal area of Yancheng City, China.

    Science.gov (United States)

    Fu, Jie; Wang, Hui; Billah, Shah M Reduwan; Yu, Hongxia; Zhang, Xiaowei

    2014-08-01

    A systematic investigation was carried out to analyze the concentration levels of heavy metals in sample seawater, sediments, and biota collected from the coastal area of Yancheng City in Jiangsu Province, China. The authors assessed the impact of these heavy metals in different environmental samples in terms of potential risks to ecology and also to the human population exposed to this area. In addition, a further investigation was carried out to test the toxicity to early-life-stage zebrafish (Danio rerio) of selected samples that were considered to pose higher levels of potential risks to ecology or human health. Chemical analysis showed relatively higher concentrations of heavy metals in the seawater and biota samples collected from Xiangshui County and Binhai County, China. The heavy metal concentrations in different samples collected from the close vicinity of Dafeng Port, China, were also considerable. In all seawater and sediment samples, heavy metals showed a relatively moderate level of risk to ecological species; for consumption of marine organisms, heavy metals had adverse impacts on human health. Toxicity assessment indicated that the selected environmental samples or their extracts had significant toxicity to zebrafish early-life stages, including lethality, teratogenicity, and hatching delay (or advance). Thus the present study provides highly useful and important information on heavy metal pollution in Jiangsu Province. © 2014 SETAC.

  13. Perfluorinated compounds in water, sediment, soil and biota from estuarine and coastal areas of Korea

    Energy Technology Data Exchange (ETDEWEB)

    Naile, Jonathan E. [Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK (Canada); Khim, Jong Seong, E-mail: jongseongkhim@korea.ac.k [Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Wang Tieyu; Chen Chunli; Luo Wei [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Science, Beijing (China); Kwon, Bong-Oh; Park, Jinsoon; Koh, Chul-Hwan [School of Earth and Environmental Sciences (Oceanography), Seoul National University, Seoul (Korea, Republic of); Jones, Paul D. [Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK (Canada); Lu Yonglong [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Science, Beijing (China); Giesy, John P. [Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK (Canada); Department of Biology and Chemistry, Center for Coastal Pollution and Conservation, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Department of Zoology, Center for Integrative Toxicology, Michigan State University, E. Lansing, MI (United States)

    2010-05-15

    Soil, sediment, water, and biota collected from the western coast of Korea were analyzed to determine occurrence and sources of perfluorinated compounds (PFCs). PFCs were significantly concentrations of PFCs were measured in some water and biological samples, while concentrations of PFCs in soils and sediments were relatively low. The most widely detected compound was found to be perfluorooctanesulfonate (PFOS), with a maximum concentration in water of 450 ng/L and in fish of 612 ng/g, dw. PFOS concentrations in water and biota were both less than those thought to cause toxicity. However, in both cases concentrations were within a factor of 10 of the toxicity threshold concentration. Concentrations of PFCs were significantly greater downstream than those upstream on the same river, suggesting point sources. Overall, the detection of PFCs at relatively great concentrations in various environmental matrixes from this region of Korea suggests that further studies characterizing PFCs and their potential risk to both humans and wildlife are needed. - Among various environmental media measured, water and biological samples showed relatively high degrees of PFC contamination with the existence of point sources mainly upstream of coastal areas in Korea.

  14. Selected chlorobornanes, polychlorinated naphthalenes and brominated flame retardants in Bjornoya (Bear Island) freshwater biota

    International Nuclear Information System (INIS)

    Evenset, Anita; Christensen, Guttorm N.; Kallenborn, Roland

    2005-01-01

    Levels of selected sparsely investigated persistent organic pollutants (POPs) have been measured in organisms from two Arctic lakes on Bjornoya (Bear Island). Elevated levels of chlorobornanes (CHBs) (up to 46.7 ng/g wet weight=ww), polybrominated diphenyl ethers (PBDEs) (up to 27.2 ng/g ww), polybrominated biphenyls (PBBs) (up to 1.1 ng/g ww) and polychlorinated naphthalenes (PCNs, only 4 congeners) (up to 62.7 pg/g ww), were measured in biota from Lake Ellasjoen. In Lake Oyangen, located only 5 km north of Ellasjoen, levels of these contaminants were significantly lower. δ 15 N-values were 7-10%o higher in organisms from Ellasjoen as compared to Oyangen. This is attributed to biological inputs related to seabird activities. The present study illustrates that contaminants such as CHBs, brominated flame retardants and PCNs accumulate in the Ellasjoen food web in a manner similar to PCBs and conventional organochlorine pesticides. Transport mechanisms that control PCB and DDT distributions, i.e. atmospheric long-range transport and biotransport by seabirds, are also relevant for the contaminants investigated in the present study. - Elevate levels of chlorobornanes, polychlorinated naphthalenes and brominated flame retardants have been measured in biota from a Norwegian Arctic lake

  15. Selected chlorobornanes, polychlorinated naphthalenes and brominated flame retardants in Bjornoya (Bear Island) freshwater biota

    Energy Technology Data Exchange (ETDEWEB)

    Evenset, Anita [Akvaplan-niva, Polar Environmental Centre, N-9296 Tromso (Norway)]. E-mail: ae@akvaplan.niva.no; Christensen, Guttorm N. [Akvaplan-niva, Polar Environmental Centre, N-9296 Tromso (Norway); Kallenborn, Roland [Norwegian Institute for Air Research, P.O. Box 100, N-2027 Kjeller (Norway)

    2005-08-15

    Levels of selected sparsely investigated persistent organic pollutants (POPs) have been measured in organisms from two Arctic lakes on Bjornoya (Bear Island). Elevated levels of chlorobornanes (CHBs) (up to 46.7 ng/g wet weight=ww), polybrominated diphenyl ethers (PBDEs) (up to 27.2 ng/g ww), polybrominated biphenyls (PBBs) (up to 1.1 ng/g ww) and polychlorinated naphthalenes (PCNs, only 4 congeners) (up to 62.7 pg/g ww), were measured in biota from Lake Ellasjoen. In Lake Oyangen, located only 5 km north of Ellasjoen, levels of these contaminants were significantly lower. {delta}{sup 15}N-values were 7-10%o higher in organisms from Ellasjoen as compared to Oyangen. This is attributed to biological inputs related to seabird activities. The present study illustrates that contaminants such as CHBs, brominated flame retardants and PCNs accumulate in the Ellasjoen food web in a manner similar to PCBs and conventional organochlorine pesticides. Transport mechanisms that control PCB and DDT distributions, i.e. atmospheric long-range transport and biotransport by seabirds, are also relevant for the contaminants investigated in the present study. - Elevate levels of chlorobornanes, polychlorinated naphthalenes and brominated flame retardants have been measured in biota from a Norwegian Arctic lake.

  16. Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound

    Directory of Open Access Journals (Sweden)

    Timothy S. Lee

    2018-02-01

    Full Text Available Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic–terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable.

  17. IOLOGICAL IMPORTANCE AND TOXICITY OF HEAVY METALS FOR BIOTA OF FRESHWATER BODIES (REVIEW

    Directory of Open Access Journals (Sweden)

    I. Hrytsyniak

    2014-06-01

    Full Text Available Purpose. To investigate the sources of scientific information on biological functions of heavy metals (Fe, Zn, Mn, Cu, Ni, Co, Pb, Cd and their negative effect on biota of fresh water bodies. Findings. A review of works of a variety of scientists showed that the majority of the studied heavy metals (Fe, Zn, Mn, Cum and Co played an important role in vital functions of freshwater organisms. The significance of other studied heavy metals (Ni, Pb, and Cd is probable or unknown. Besides biological importance, we also know about toxicity of heavy metals – a group of mineral polluting substances, which are the most distributed and dangerous for biota. Their negative effect includes drastic deterioration of conditions for existence of the majority of aquatic organisms, some species disappear, others reduce their number, components of trophic chains are lost, links in ecosystems become broken, and productivity of biocenoses decreases. Practical value. An array of generalized information will be useful for scientists who investigate freshwater ecosystems and effect of toxicants on them, in particular heavy metals.

  18. Effects of sea ice on Arctic biota: an emerging crisis discipline.

    Science.gov (United States)

    Macias-Fauria, Marc; Post, Eric

    2018-03-01

    The rapid decline in Arctic sea ice (ASI) extent, area and volume during recent decades is occurring before we can understand many of the mechanisms through which ASI interacts with biological processes both at sea and on land. As a consequence, our ability to predict and manage the effects of this enormous environmental change is limited, making this a crisis discipline Here, we propose a framework to study these effects, defining direct effects as those acting on life-history events of Arctic biota, and indirect effects , where ASI acts upon biological systems through chains of events, normally involving other components of the physical system and/or biotic interactions. Given the breadth and complexity of ASI's effects on Arctic biota, Arctic research requires a truly multidisciplinary approach to address this issue. In the absence of effective global efforts to tackle anthropogenic global warming, ASI will likely continue to decrease, compromising the conservation of many ASI-related taxonomic groups and ecosystems. Mitigation actions will rely heavily on the knowledge acquired on the mechanisms and components involved with the biological effects of ASI. © 2018 The Author(s).

  19. Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound.

    Science.gov (United States)

    Lee, Timothy S; Toft, Jason D; Cordell, Jeffery R; Dethier, Megan N; Adams, Jeffrey W; Kelly, Ryan P

    2018-01-01

    Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic-terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness) from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable.

  20. Nutrients removal using moving beds with aeration cycles

    International Nuclear Information System (INIS)

    Martin Martin, A.; Foresti, E.; Garcia-Encina, P. A.

    2009-01-01

    Moving Bed Biofilm Reactors (MBBR) are based on the biomass growth over a media that moves into the reactor due to aeration, mechanical agitation or recirculation. These reactors have been gaining popularity and they are employed in hundreds of plants everywhere with different treatment purposes (organic matter removal, nitrification/denitrification), both for urban and industrial wastewater. (Author)

  1. Dissecting the role of viruses in marine nutrient cycling

    DEFF Research Database (Denmark)

    Shelford, Emma J.; Jørgensen, Niels O. G.; Rasmussen, Susan

    2014-01-01

    Lysis of marine bacteria by viruses releases a range of organic compounds into the environment, including D- and L-amino acids, but the uptake of these compounds by other bacteria is not well characterized. This study determined that Photobacterium sp. strain SKA34 (Gamma - proteobacteria...... for Photobacterium sp. growth, thus causing a net uptake of ammonium. In contrast, only 1.51 μmol l−1 of the 4.77 μmol l−1 of the total dissolved combined amino acids (DCAAs) were taken up, indicating that a fraction of lysate-derived DCAAs were semi-labile or refractory to bacterial uptake. Both D- and L-amino acid...... uptake rates were approximately proportional to their concentrations, indicating similar availability for each enantiomer and unsaturated uptake rates. These results imply that under high C:N conditions, both D-amino acids (mainly found in bacterial cell walls) and L-amino acids (found in proteins...

  2. Development of Gene Centric Modeling for Nutrient Cycling

    Science.gov (United States)

    opportunity to participate in the development of a gene-centric model to help predict potential changes in the biogeochemistry of aquatic ecosystems that may arise from anthropogenic stressors and management decisions

  3. Nutrient cycling by Acacia erioloba (syn. Acacia giraffae ) in ...

    African Journals Online (AJOL)

    arid areas of Southern Africa because of the many benefits it offers to local communities. However, little quantitative plant and soil data exist to explain its ability to enhance soil fertility under local conditions. Paired soil samples taken under and ...

  4. Ecologically sustainable development in dairy farms II: Nutrient cycling

    Science.gov (United States)

    In Mexico, there is not a specific regulation dealing with manure and wastewater in confined livestock farms. In the case of dairy farms that have agricultural areas for the production of forage crops, there are some "Good Management Practices", focused on the use of manure as a source of nitrogen a...

  5. WERF Nutrient Challenge investigates limits of nutrient removal technologies.

    Science.gov (United States)

    Neethling, J B; Clark, D; Pramanik, A; Stensel, H D; Sandino, J; Tsuchihashi, R

    2010-01-01

    The WERF Nutrient Challenge is a multi-year collaborative research initiative established in 2007 to develop and provide current information about wastewater treatment nutrients (specifically nitrogen and phosphorus in wastewater), their characteristics, and bioavailability in aquatic environments to help regulators make informed decisions. The Nutrient Challenge will also provide data on nutrient removal so that treatment facilities can select sustainable, cost-effective methods and technologies to meet permit limits. To meet these goals, the Nutrient Challenge has teamed with a wide array of utilities, agencies, consultants, universities and other researchers and practitioners to collaborate on projects that advance these goals. The Nutrient Challenge is focusing on a different approach to collaborating and leveraging resources (financial and intellectual) on research projects by targeting existing projects and research that correspond with its goals and funding those aspects that the Nutrient Challenge identified as a priority. Because the Nutrient Challenge is focused on collaboration, outreach is an absolutely necessary component of its effectiveness. Through workshops, webinars, a web portal and online compendium, published papers, and conference lectures, the Nutrient Challenge is both presenting important new information, and soliciting new partnerships.

  6. The response of soil biota to phosphate fertilization in grassland columns

    Science.gov (United States)

    Ikoyi, Israel; Winstanley, Henry; Fowler, Andrew; Schmalenberger, Achim

    2017-04-01

    The United Nations has predicted that food production is expected to rise by 50% in the year 2020 to feed the increasing world population. Grasslands play significant roles in food production and occupy about 70% of the world's agricultural land. However, intensive use of inorganic fertilizers often associated with increased food production can lead to poor soil quality and environmental pollution. For instance, excessive phosphorus (P) application can lead to eutrophication in surface waters. Although P plays vital roles in many metabolic processes in plants, its primary source rock phosphate is finite. Consequently, the development of more P efficient agricultural systems is paramount. P cycling within the microbial biomass is essential to the P cycle within the soil with its key pathways for P mobilization and mineralization from various soil pools into plant available forms. In this study, soil columns were setup in a greenhouse using a P deficient Irish soil (P index 1). The columns were planted with Lolium perenne and fertilized with 0, 5, 10 and 20 kg/ha inorganic P representing control, low, medium and high rates respectively alongside a full complement of other nutrients. Each treatment was replicated six times and managed for 14 weeks. Results after 14 weeks showed that the weekly measurements of phosphate at different soil depths identified only traces of P in soil solution for the duration of 14 weeks, even after P application. There was a significant increase in alkaline and acid phosphatase activities with the high P compared to the control but no significant effect on plant shoot and root biomass, abundances of cultivable calcium phosphate-, phytate- and phosphonate-utilizing bacteria upon P fertilization. L. perenne rhizosphere of the highest P treatment had significantly lower abundance of bacterial phoD genes, mycorrhizal hyphal and arbuscular colonization rates compared to the control. Likewise, the abundance of bacterial- and fungal

  7. Nutrient profiling for regulatory purposes.

    Science.gov (United States)

    Rayner, Mike

    2017-08-01

    In this paper, I first provide definitions of nutrient profiling and of a nutrient profile model. I set out the purposes of nutrient profiling: both general and specific. I give two examples of nutrient profile models that have been developed for regulatory purposes by the Food Standards Agency (FSA) in the UK and the WHO for its European Region - the UK FSA/Ofcom and the WHO-Euro models - and compare the way the models are constructed and function, how they have been developed, the extent to which they have been tested and validated and their use in regulation. Finally I draw some conclusions about the future use of nutrient profiling for regulatory purposes. I argue that its full potential has yet to be realised and give some reasons why. I pose some urgent research questions with respect to nutrient profiling.

  8. [Effects of biochar on soil nutrients leaching and potential mechanisms: A review].

    Science.gov (United States)

    Liu, Yu-xue; Lyu, Hao-hao; Shi, Yan; Wang, Yao-feng; Zhong, Zhe-ke; Yang, Sheng-mao

    2015-01-01

    Controlling soil nutrient leaching in farmland ecosystems has been a hotspot in the research field of agricultural environment. Biochar has its unique physical and chemical properties, playing a significant role in enhancing soil carbon storage, improving soil quality and increasing crop yield. As a kind of new exogenous material, biochar has the potential in impacting soil nutrient cycling directly or indirectly, and has profound influences on soil nutrient leaching. This paper analyzed the intrinsic factors affecting how biochar affects soil nutrient leaching, such as the physical and chemical properties of biochar, and the interaction between biochar and soil organisms. Then the latest literatures regarding the external factors, including biochar application rates, soil types, depth of soil layer, fertilization conditions and temporal dynamics, through which biochar influences soil nutrient (especially nitrogen and phosphorus) leaching were reviewed. On that basis, four related action mechanisms were clarified, including direct adsorption of nutrients by biochar due to its micropore structure or surface charge, influencing nutrient leaching through increasing soil water- holding capacity, influencing nutrient cycling through the interaction with soil microbes, and preferential transport of absorbed nutrients by fine biochar particles. At last future research directions for better understanding the interactions between biochar and nutrient leaching in the soil were proposed.

  9. Proceedings of the workshop on 'effect of radiation on non-human biota'

    International Nuclear Information System (INIS)

    Takahashi, Sentaro; Takahashi, Tomoyuki

    2011-03-01

    Safety assessment and protection for the radiation exposure were so far mainly based on the radiation effects on human health, because it has been generally recognized that, when human beings are protected, other environmental life, at least in the level of species or groups, will be protected from the radiation hazards, even if individuals may be affected. Recently, with increasing concern on environmental protection, a new framework of radiation protection has been proposed, where non-human biota as well as human beings is included. Researches on the environmental radiation protection need a contribution of multi-disciplinary researchers as similar to the other environmental sciences. Especially, a research field on the biological effect of radiation on non-human biota is fundamental and essential. Therefore, we planned the Workshop entitled Effect of Radiation on the Non-human Biota this time. All the 13 papers presented at the entitled meeting are indexed individually. (J.P.N.)

  10. An integrated decision support system for wastewater nutrient recovery and recycling to agriculture

    Science.gov (United States)

    Roy, E. D.; Bomeisl, L.; Cornbrooks, P.; Mo, W.

    2017-12-01

    Nutrient recovery and recycling has become a key research topic within the wastewater engineering and nutrient management communities. Several technologies now exist that can effectively capture nutrients from wastewater, and innovation in this area continues to be an important research pursuit. However, practical nutrient recycling solutions require more than capable nutrient capture technologies. We also need to understand the role that wastewater nutrient recovery and recycling can play within broader nutrient management schemes at the landscape level, including important interactions at the nexus of food, energy, and water. We are developing an integrated decision support system that combines wastewater treatment data, agricultural data, spatial nutrient balance modeling, life cycle assessment, stakeholder knowledge, and multi-criteria decision making. Our goals are to: (1) help guide design decisions related to the implementation of sustainable nutrient recovery technology, (2) support innovations in watershed nutrient management that operate at the interface of the built environment and agriculture, and (3) aid efforts to protect aquatic ecosystems while supporting human welfare in a circular nutrient economy. These goals will be realized partly through the assessment of plausible alternative scenarios for the future. In this presentation, we will describe the tool and focus on nutrient balance results for the New England region. These results illustrate that both centralized and decentralized wastewater nutrient recovery schemes have potential to transform nutrient flows in many New England watersheds, diverting wastewater N and P away from aquatic ecosystems and toward local or regional agricultural soils where they can offset a substantial percentage of imported fertilizer. We will also highlight feasibility criteria and next steps to integrate stakeholder knowledge, economics, and life cycle assessment into the tool.

  11. Nutrient limitation in Northern Gulf of Mexico (NGOM: phytoplankton communities and photosynthesis respond to nutrient pulse.

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    Full Text Available Although the Mississippi-Atchafalaya River system exports large amounts of nutrients to the Northern Gulf of Mexico annually, nutrient limitation of primary productivity still occurs offshore, acting as one of the major factors controlling local phytoplankton biomass and community structure. Bioassays were conducted for 48 hrs at two stations adjacent to the river plumes in April and August 2012. High Performance of Liquid Chromatography (HPLC combined with ChemTax and a Fluorescence Induction and Relaxation (FIRe system were combined to observe changes in the phytoplankton community structure and photosynthetic activity. Major fluorescence parameters (Fo, Fv/Fm performed well to reveal the stimulating effect of the treatments with nitrogen (N-nitrate and with nitrogen plus phosphate (+NPi. HPLC/ChemTax results showed that phytoplankton community structure shifted with nitrate addition: we observed an increase in the proportion of diatoms and prasinophytes and a decrease in cyanobacteria and prymnesiophytes. These findings are consistent with predictions from trait-based analysis which predict that phytoplankton groups with high maximum growth rates (μmax and high nutrient uptake rates (Vmax readily take advantage of the addition of limiting nutrients. Changes in phytoplankton community structure, if persistent, could trigger changes of particular organic matter fluxes and alter the micro-food web cycles and bottom oxygen consumption.

  12. Plant Diversity Surpasses Plant Functional Groups and Plant Productivity as Driver of Soil Biota in the Long Term

    Science.gov (United States)

    Eisenhauer, Nico; Milcu, Alexandru; Sabais, Alexander C. W.; Bessler, Holger; Brenner, Johanna; Engels, Christof; Klarner, Bernhard; Maraun, Mark; Partsch, Stephan; Roscher, Christiane; Schonert, Felix; Temperton, Vicky M.; Thomisch, Karolin; Weigelt, Alexandra; Weisser, Wolfgang W.; Scheu, Stefan

    2011-01-01

    Background One of the most significant consequences of contemporary global change is the rapid decline of biodiversity in many ecosystems. Knowledge of the consequences of biodiversity loss in terrestrial ecosystems is largely restricted to single ecosystem functions. Impacts of key plant functional groups on soil biota are considered to be more important than those of plant diversity; however, current knowledge mainly relies on short-term experiments. Methodology/Principal Findings We studied changes in the impacts of plant diversity and presence of key functional groups on soil biota by investigating the performance of soil microorganisms and soil fauna two, four and six years after the establishment of model grasslands. The results indicate that temporal changes of plant community effects depend on the trophic affiliation of soil animals: plant diversity effects on decomposers only occurred after six years, changed little in herbivores, but occurred in predators after two years. The results suggest that plant diversity, in terms of species and functional group richness, is the most important plant community property affecting soil biota, exceeding the relevance of plant above- and belowground productivity and the presence of key plant functional groups, i.e. grasses and legumes, with the relevance of the latter decreasing in time. Conclusions/Significance Plant diversity effects on biota are not only due to the presence of key plant functional groups or plant productivity highlighting the importance of diverse and high-quality plant derived resources, and supporting the validity of the singular hypothesis for soil biota. Our results demonstrate that in the long term plant diversity essentially drives the performance of soil biota questioning the paradigm that belowground communities are not affected by plant diversity and reinforcing the importance of biodiversity for ecosystem functioning. PMID:21249208

  13. Plant diversity surpasses plant functional groups and plant productivity as driver of soil biota in the long term.

    Directory of Open Access Journals (Sweden)

    Nico Eisenhauer

    2011-01-01

    Full Text Available One of the most significant consequences of contemporary global change is the rapid decline of biodiversity in many ecosystems. Knowledge of the consequences of biodiversity loss in terrestrial ecosystems is largely restricted to single ecosystem functions. Impacts of key plant functional groups on soil biota are considered to be more important than those of plant diversity; however, current knowledge mainly relies on short-term experiments.We studied changes in the impacts of plant diversity and presence of key functional groups on soil biota by investigating the performance of soil microorganisms and soil fauna two, four and six years after the establishment of model grasslands. The results indicate that temporal changes of plant community effects depend on the trophic affiliation of soil animals: plant diversity effects on decomposers only occurred after six years, changed little in herbivores, but occurred in predators after two years. The results suggest that plant diversity, in terms of species and functional group richness, is the most important plant community property affecting soil biota, exceeding the relevance of plant above- and belowground productivity and the presence of key plant functional groups, i.e. grasses and legumes, with the relevance of the latter decreasing in time.Plant diversity effects on biota are not only due to the presence of key plant functional groups or plant productivity highlighting the importance of diverse and high-quality plant derived resources, and supporting the validity of the singular hypothesis for soil biota. Our results demonstrate that in the long term plant diversity essentially drives the performance of soil biota questioning the paradigm that belowground communities are not affected by plant diversity and reinforcing the importance of biodiversity for ecosystem functioning.

  14. Vegetation composition, nutrient, and sediment dynamics along a floodplain landscape

    Science.gov (United States)

    Rybicki, Nancy B.; Noe, Gregory; Hupp, Cliff R.; Robinson, Myles

    2015-01-01

    Forested floodplains are important landscape features for retaining river nutrients and sediment loads but there is uncertainty in how vegetation influences nutrient and sediment retention. In order to understand the role of vegetation in nutrient and sediment trapping, we quantified species composition and the uptake of nutrients in plant material relative to landscape position and ecosystem attributes in an urban, Piedmont watershed in Virginia, USA. We investigated in situ interactions among vegetative composition, abundance, carbon (C), nitrogen (N) and phosphorus (P) fluxes and ecosystem attributes such as water level, shading, soil nutrient mineralization, and sediment deposition. This study revealed strong associations between vegetation and nutrient and sediment cycling processes at the plot scale and in the longitudinal dimension, but there were few strong patterns between these aspects at the scale of geomorphic features (levee, backswamp, and toe-slope). Patterns reflected the nature of the valley setting rather than a simple downstream continuum. Plant nutrient uptake and sediment trapping were greatest at downstream sites with the widest floodplain and lowest gradient where the hydrologic connection between the floodplain and stream is greater. Sediment trapping increased in association with higher herbaceous plant coverage and lower tree canopy density that, in turn, was associated with a more water tolerant tree community found in the lower watershed but not at the most downstream site in the watershed. Despite urbanization effects on the hydrology, this floodplain functioned as an efficient nutrient trap. N and P flux rates of herbaceous biomass and total litterfall more than accounted for the N and P mineralization flux rate, indicating that vegetation incorporated nearly all mineralized nutrients into biomass.

  15. Nutrients and neurodevelopment: lipids.

    Science.gov (United States)

    González, Horacio F; Visentin, Silvana

    2016-10-01

    Nutrients, lipids in particular, make up the central nervous system structure and play major functional roles: they stimulate development, migration, and nerve cell differentiation. They are part of gray matter, white matter, nerve nuclei, and synaptogenesis. Breast milk contains lipids which are crucial for infant brain development. The lipid profile of breast milk was used as a guideline for the development of breast milk substitutes. However, to date, no substitute has matched it. Complementary feeding should include docosahexaenoic acid, arachidonic acid, other polyunsaturated fatty acids, saturated fatty acids, and complex lipids found in milk fat. The lipid composition of breast milk depends on maternal intake and nutritional status during pregnancy and breast-feeding. It has a great impact on development. Our goal is to review scientific literature regarding the role of lipids on infant brain development and the importance of breast milk lipid composition, maternal diet, and complementary feeding. Sociedad Argentina de Pediatría.

  16. Nutrient and Anti nutrient Composition of Jams Prepared from ...

    African Journals Online (AJOL)

    Objective: This study was aimed at determining the nutrient and anti nutrient composition of jams prepared from Hibiscus sabdariffa calyx extract Materials and methods: Hibiscus sabdariffa calyx, otherwise known as Red Roselle usually processed into a refreshing drink “Zobo” in Nigeria was extracted with distilled water ...

  17. TOXIC EFFECT OF PESTICIDES ON THE BIOTA OF FRESHWATER RESERVOIRS OF UKRAINE (A REVIEW

    Directory of Open Access Journals (Sweden)

    N. Kolesnyk

    2015-12-01

    Full Text Available Purpose. To analyze scientific sources on the studies of toxic and lethal concentrations of pesticides on phytoplankton, zooplankton, zoobenthos and fish in current conditions of Ukraine. Findings. A review of works of a variety of scientists showed that pesticides with different chemical origins have disastrous effects on everyone without the exception of freshwater biota organisms. The article highlights the peculiarities of the toxic effects of pesticides of major chemical groups, which are used or stored in Ukraine. Their toxic and lethal concentrations for the major species of phytoplankton, zooplankton, zoobenthos and ichthyofauna reservoirs are considered. The data on basic features of behavioral reactions of aquatic organisms on poisoning by pesticides are provided. The basic structural and systemic diosrders of homeostasis of the organisms of aquatic biota are described. The effect of pesticides on phytoplankton needs further research, however, is was found that they have common feature as the disturbace of photosynthesis process and accumulation. In turn, this provoques kills in water bodies and poisoning of phytoplanctivorous fish. Zooplanktonic organisms are highly sensitive to pesticides; hence they can be used as an indicator of the state of fresh water. It was found that, pesticides depending on their concentration have different toxic effects on zooplankton organisms. The effect of pesticides on benthic organisms was little investigated. It is known that benthic communities respond to the presence of pesticide by changes in species composition, number of species, abundance and biomass of benthos in general and individual taxonomic groups of benthic invertebrates. The toxicity of pesticides for fish depends on their chemical nature, the form of the preparation, dose, fish species and age, water temperature and the content of oxygen and salts. In particular, juvenile fish are much more sensitive to the chemicals, and an increase in

  18. Relationships at the aboveground-belowground interface: plants, soil biota and soil processes

    NARCIS (Netherlands)

    Porazinska, D.L.; Bardgett, R.D.; Postma-Blaauw, M.B.; Hunt, H.W.; Parsons, A.N.; Seastedt, T.R.; Wall, D.M.

    2003-01-01

    Interactions at the aboveground-below ground interface provide important feedbacks that regulate ecosystem processes. Organisms within soil food webs are involved in processes of decomposition and nutrient mineralization, and their abundance and activity have been linked to plant ecophysiological

  19. Potassium cycling and losses in grassland systems : a review

    NARCIS (Netherlands)

    Kayser, M; Isselstein, J

    Cycling of potassium in grassland systems has received relatively little attention in research and practice in recent years. Balanced nutrient systems require consideration of nutrients other than nitrogen (N). Potassium (K) is needed in large amounts and is closely related to N nutrition. In

  20. Mortality hotspots: nitrogen cycling in forest soils during vertebrate decomposition

    Science.gov (United States)

    Decomposing plants and animals fundamentally transform their surrounding environments, and serve as a critical source of limiting nutrients for macro- and micro-fauna. Animal mortality hotspots alter soil biogeochemical cycles, and these natural ephemeral nutrient patches are important for maintaini...

  1. Nutrient management in substrate systems

    NARCIS (Netherlands)

    Sonneveld, C.; Voogt, W.

    2009-01-01

    Speaking about nutrient solutions in soilless cultivation, different solutions can be discerned. Originally, in soilless culture only one nutrient solution was taken into account, being the solution in the containers in which the plants were grown. Such solutions were intensively moved by air

  2. The Nutrient Density of Snacks

    Directory of Open Access Journals (Sweden)

    Julie Hess BA

    2017-03-01

    Full Text Available Background: Although Americans receive almost a quarter of their daily energy from snacks, snacking remains a poorly defined and understood eating occasion. However, there is little dietary guidance about choosing snacks. Families, clinicians, and researchers need a comprehensive approach to assessing their nutritional value. Objective: To quantify and compare the nutrient density of commonly consumed snacks by their overall nutrient profiles using the Nutrient-Rich Foods (NRF Index 10.3. Methods: NRF Index scores were calculated for the top 3 selling products (based on 2014 market research data in different snack categories. These NRF scores were averaged to provide an overall nutrient-density score for each category. Results: Based on NRF scores, yogurt (55.3, milk (52.5, and fruit (30.1 emerged as the most nutrient-dense snacks. Ice cream (−4.4, pies and cakes (−11.1, and carbonated soft drinks (−17.2 emerged as the most nutrient-poor snacks. Conclusions: The NRF Index is a useful tool for assessing the overall nutritional value of snacks based on nutrients to limit and nutrients to encourage.

  3. Studies on monitoring of river water quality by neutron activation analysis of aquatic biota

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Masao; Tanizaki, Yoshiyuki; Shimokawa, Toshinari (Tokyo Metropolitan Isotope Research Center (Japan))

    1990-02-01

    In order to clarify the possibility of a new method to monitor the river water quality by neutron activation analysis of aquatic biota, the followings were investigated: (1) the species of fish, water plants and aquatic insects which we can collect easily in Tamagawa River basin, (2) problems in pre-treatment of biological samples, and (3) relationship between elemental concentrations in biological samples and in river water. We found that the biological species suitable for the analytical investigation are Carassius auratus langsdorfii (GINBUNA), Pseudorasbora parva (MOTSUGO), Potamageton orientalis Hagst. (AINOKOITOMO), Elodea nuttalli (Planch.) St. John (KOKANADAMO), Cheuma-topsyche brevilineata (Iwata) (KOGATASHIMATOBIKERA) and Hydropsyche orientalis Martynov (URUMASHIMATOBIKERA). Fish samples showed apparently different concentrations of elements in each part of their bodies. Simple washing of water plants and aquatic insects was found not to be enough to eliminate rock-oriented particles. Such elements as Ag, Mn and Zn showed relationships of their concentrations between in biological samples and in river water. (author).

  4. Reviewing the serotonin reuptake inhibitors (SSRIs) footprint in the aquatic biota: uptake, bioaccumulation and ecotoxicology.

    Science.gov (United States)

    Silva, Liliana J G; Pereira, André M P T; Meisel, Leonor M; Lino, Celeste M; Pena, Angelina

    2015-02-01

    Selective serotonin re-uptake inhibitors (SSRIs) antidepressants are amongst the most prescribed pharmaceutical active substances throughout the world. Their presence, already described in different environmental compartments such as wastewaters, surface, ground and drinking waters, and sediments, and their remarkable effects on non-target organisms justify the growing concern about these emerging environmental pollutants. A comprehensive review of the literature data with focus on their footprint in the aquatic biota, namely their uptake, bioaccumulation and both acute and chronic ecotoxicology is presented. Long-term multigenerational exposure studies, at environmental relevant concentrations and in mixtures of related compounds, such as oestrogenic endocrine disruptors, continue to be sparse and are imperative to better know their environmental impact. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Sensing of Scent, Fragrance, Smell, and Odor Emissions from Biota Sources

    Directory of Open Access Journals (Sweden)

    Ki-Hyun Kim

    2014-04-01

    Full Text Available People encounter enormous numbers of chemicals present in the outdoor atmosphere and/or in the various facilities they use daily. Despite such diversity, not many of them have necessarily the potential to draw human’s nasal attraction if their perception thresholds are in general not sufficiently low enough, regardless of abundance. In this sense, many types of scents, musks, fragrances, smells, odors, and pheromones are unique enough to draw a great deal of attention mainly by their presence at or near threshold levels which are far lower than those of common chemicals with poor odorant characteristics. It is known that most of the diverse characters of odor-related ingredients or expressions are commonly produced from various biota sources present in the biosphere, e.g., fauna, flora, bacteria, fruits, flowers, trees, meats, fresh/decaying foods, etc.

  6. Filling knowledge gaps in radiation protection methodologies for non-human biota. Final summary report

    International Nuclear Information System (INIS)

    Brown, J.; Gjelsvik, R.; Holm, E.; Roos, P.; Saxen, R.; Outola, I.

    2009-03-01

    The activities of the GAPRAD project are summarised in this report. The background and rationale to GAPRAD are presented and explained. Most notably this relates to a lack of information on naturally occuring radionuclides in terrestrial and aquatic systems that have direct applicability for use in environmental impact assessments. Results from field activities are presented from the Dovrefjell area in Norway (terrestrial study) and selected lake and brackish water systems in Finland. The data mainly concern activity concentrations of Po-210 in environmental media and selected biota allowing concentration ratios to be derived where appropriate. Furthermore, details in relation to Po-210 uptake and biokinetics in humans based on experimental work conducted within the project are presented. (au)

  7. Review of emerging contaminants in aquatic biota from Latin America: 2002-2016.

    Science.gov (United States)

    Llorca, Marta; Farré, Marinella; Eljarrat, Ethel; Díaz-Cruz, Sílvia; Rodríguez-Mozaz, Sara; Wunderlin, Daniel; Barcelo, Damià

    2017-07-01

    Although it is known that emerging contaminants are widespread all over the globe, there is a gap of information about their distribution in some geographical areas, such as Latin America. The present bibliographic work reviews the available literature about the presence of organic emerging contaminants in Latin American freshwater and marine biota between 2002 and 2016 and includes 23 works from Argentina, Brazil, Chile, Colombia, Mexico, and Nicaragua. In particular, the present review provides an overview of the occurrence of continuously present contaminants such as pharmaceuticals, personal care products, and pyrethroid insecticides, as well as the new groups of persistent organic pollutants, the halogenated flame retardants and the perfluoroalkyl substances. A wide overview is provided, considering not only occurrence data but also effects and potential transfer through the food chain. Environ Toxicol Chem 2017;36:1716-1727. © 2016 SETAC. © 2016 SETAC.

  8. Extraction of microplastic from biota: recommended acidic digestion destroys common plastic polymers

    DEFF Research Database (Denmark)

    Enders, Kristina; Lenz, Robin; Beer, Sabrina

    2017-01-01

    The chemical digestion of tissue from marine biota for microplastic analysis is currently conducted following a variety of protocols published in scientific literature. Often there is a lack of information on whether and to which degree the applied chemicals are destructive to microplastic...... particles of various polymer types. In the present study we report that a digestion protocol recently recommended by ICES using nitric and perchloric acid has strong detrimental effects on several common plastic polymers, in particular polyamide and polyurethane and to a lesser degree acrylonitrile...... butadiene styrene, polymethyl methacrylate and polyvinylchloride. Raman spectroscopic measurements revealed changes in peak occurrence and intensity for several polymers that did not otherwise show visual macroscopic changes. We developed and tested an alkaline digestion protocol in order to preserve small...

  9. Isolation of microplastics in biota-rich seawater samples and marine organisms

    Science.gov (United States)

    Cole, Matthew; Webb, Hannah; Lindeque, Pennie K.; Fileman, Elaine S.; Halsband, Claudia; Galloway, Tamara S.

    2014-03-01

    Microplastic litter is a pervasive pollutant present in aquatic systems across the globe. A range of marine organisms have the capacity to ingest microplastics, resulting in adverse health effects. Developing methods to accurately quantify microplastics in productive marine waters, and those internalized by marine organisms, is of growing importance. Here we investigate the efficacy of using acid, alkaline and enzymatic digestion techniques in mineralizing biological material from marine surface trawls to reveal any microplastics present. Our optimized enzymatic protocol can digest >97% (by weight) of the material present in plankton-rich seawater samples without destroying any microplastic debris present. In applying the method to replicate marine samples from the western English Channel, we identified 0.27 microplastics m-3. The protocol was further used to extract microplastics ingested by marine zooplankton under laboratory conditions. Our findings illustrate that enzymatic digestion can aid the detection of microplastic debris within seawater samples and marine biota.

  10. Isolation of microplastics in biota-rich seawater samples and marine organisms

    Science.gov (United States)

    Cole, Matthew; Webb, Hannah; Lindeque, Pennie K.; Fileman, Elaine S.; Halsband, Claudia; Galloway, Tamara S.

    2014-01-01

    Microplastic litter is a pervasive pollutant present in aquatic systems across the globe. A range of marine organisms have the capacity to ingest microplastics, resulting in adverse health effects. Developing methods to accurately quantify microplastics in productive marine waters, and those internalized by marine organisms, is of growing importance. Here we investigate the efficacy of using acid, alkaline and enzymatic digestion techniques in mineralizing biological material from marine surface trawls to reveal any microplastics present. Our optimized enzymatic protocol can digest >97% (by weight) of the material present in plankton-rich seawater samples without destroying any microplastic debris present. In applying the method to replicate marine samples from the western English Channel, we identified 0.27 microplastics m−3. The protocol was further used to extract microplastics ingested by marine zooplankton under laboratory conditions. Our findings illustrate that enzymatic digestion can aid the detection of microplastic debris within seawater samples and marine biota. PMID:24681661

  11. Filling knowledge gaps in radiation protection methodologies for non-human biota. Final summary report

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.; Gjelsvik, R. (Norwegian Radiation Protection Authority (Norway)); Holm, E. (Univ. of Lund (Sweden)); Roos, P. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Saxen, R.; Outola, I. (Radiation and Nuclear Safety Authority (Finland))

    2009-03-15

    The activities of the GAPRAD project are summarised in this report. The background and rationale to GAPRAD are presented and explained. Most notably this relates to a lack of information on naturally occuring radionuclides in terrestrial and aquatic systems that have direct applicability for use in environmental impact assessments. Results from field activities are presented from the Dovrefjell area in Norway (terrestrial study) and selected lake and brackish water systems in Finland. The data mainly concern activity concentrations of Po-210 in environmental media and selected biota allowing concentration ratios to be derived where appropriate. Furthermore, details in relation to Po-210 uptake and biokinetics in humans based on experimental work conducted within the project are presented. (au)

  12. A kinetic-allometric approach to predicting tissue radionuclide concentrations for biota

    International Nuclear Information System (INIS)

    Higley, K.A.; Domotor, S.L.; Antonio, E.J.

    2003-01-01

    Allometry, or the biology of scaling, is the study of size and its consequences. It has become a useful tool for comparative physiology. There are several allometric equations that relate body size to many parameters, including ingestion rate, lifespan, inhalation rate, home range and more. While these equations were originally derived from empirical observations, there is a growing body of evidence that these relationships have their origins in the dynamics of energy transport mechanisms. As part of an ongoing effort by the Department of Energy in developing generic methods for evaluating radiation dose to biota, we have examined the utility of applying allometric techniques to predicting radionuclide tissue concentration across a large range of terrestrial and riparian species of animals. This particular study examined 23 radionuclides. Initial investigations suggest that the allometric approach can provide a useful tool to derive limiting values of uptake and elimination factors for animals

  13. A kinetic-allometric approach to predicting tissue radionuclide concentrations for biota

    Energy Technology Data Exchange (ETDEWEB)

    Higley, K.A. E-mail: higley@engr.orst.edu; Domotor, S.L.; Antonio, E.J

    2003-07-01

    Allometry, or the biology of scaling, is the study of size and its consequences. It has become a useful tool for comparative physiology. There are several allometric equations that relate body size to many parameters, including ingestion rate, lifespan, inhalation rate, home range and more. While these equations were originally derived from empirical observations, there is a growing body of evidence that these relationships have their origins in the dynamics of energy transport mechanisms. As part of an ongoing effort by the Department of Energy in developing generic methods for evaluating radiation dose to biota, we have examined the utility of applying allometric techniques to predicting radionuclide tissue concentration across a large range of terrestrial and riparian species of animals. This particular study examined 23 radionuclides. Initial investigations suggest that the allometric approach can provide a useful tool to derive limiting values of uptake and elimination factors for animals.

  14. Pu-239 organ specific dosimetric model applied to non-human biota

    Science.gov (United States)

    Kaspar, Matthew Jason

    There are few locations throughout the world, like the Maralinga nuclear test site located in south western Australia, where sufficient plutonium contaminate concentration levels exist that they can be utilized for studies of the long-term radionuclide accumulation in non-human biota. The information obtained will be useful for the potential human users of the site while also keeping with international efforts to better understand doses to non-human biota. In particular, this study focuses primarily on a rabbit sample set collected from the population located within the site. Our approach is intended to employ the same dose and dose rate methods selected by the International Commission on Radiological Protection and adapted by the scientific community for similar research questions. These models rely on a series of simplifying assumptions on biota and their geometry; in particular; organisms are treated as spherical and ellipsoidal representations displaying the animal mass and volume. These simplifications assume homogeneity of all animal tissues. In collaborative efforts between Colorado State University and the Australian Nuclear Science and Technology Organisation (ANSTO), we are expanding current knowledge on radionuclide accumulation in specific organs causing organ-specific dose rates, such as Pu-239 accumulating in bone, liver, and lungs. Organ-specific dose models have been developed for humans; however, little has been developed for the dose assessment to biota, in particular rabbits. This study will determine if it is scientifically valid to use standard software, in particular ERICA Tool, as a means to determine organ-specific dosimetry due to Pu-239 accumulation in organs. ERICA Tool is normally applied to whole organisms as a means to determine radiological risk to whole ecosystems. We will focus on the aquatic model within ERICA Tool, as animal organs, like aquatic organisms, can be assumed to lie within an infinite uniform medium. This model would

  15. Anthropogenic microfibres pollution in marine biota. A new and simple methodology to minimize airborne contamination.

    Science.gov (United States)

    Torre, Michele; Digka, Nikoletta; Anastasopoulou, Aikaterini; Tsangaris, Catherine; Mytilineou, Chryssi

    2016-12-15

    Research studies on the effects of microlitter on marine biota have become more and more frequent the last few years. However, there is strong evidence that scientific results based on microlitter analyses can be biased by contamination from air transported fibres. This study demonstrates a low cost and easy to apply methodology to minimize the background contamination and thus to increase results validity. The contamination during the gastrointestinal content analysis of 400 fishes was tested for several sample processing steps of high risk airborne contamination (e.g. dissection, stereomicroscopic analysis, and chemical digestion treatment for microlitter extraction). It was demonstrated that, using our methodology based on hermetic enclosure devices, isolating the working areas during the various processing steps, airborne contamination reduced by 95.3%. The simplicity and low cost of this methodology provide the benefit that it could be applied not only to laboratory but also to field or on board work. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Effects of shoreline treatment methods on intertidal biota in Prince William Sound

    International Nuclear Information System (INIS)

    Lees, D.C.; Houghton, J.P.; Driskell, W.B.

    1993-01-01

    Several studies conducted in Prince William Sound during 1989 were directed at assessing short term biological effects of treatment methods considered or employed for treating oil contaminated beaches. The four treatment alternatives evaluated in this paper are: low pressure warm water wash (LP-WW); high pressure hot water wash (HP-HW); the dispersant Corexit 7664; and the beach cleaner Corexit 9580 M2. Effects on the biota were assessed primarily on the basis of changes in the abundance of dominant taxa and the magnitude of selected community attributes (such as percent cover by algae or animals, and number of taxa). Significant reductions in one or more community or population attributes, and increases in the percent of dead mussels were observed in response to all types of treatment but the strongest and most consistent effects were observed following high pressure hot water treatment, which was also accompanied by heavy mortality in rockweed. Generally, the programs were not designed to discriminate among the potential causes of damage. However, available data suggest that neither chemical nor LP-WW treatments caused significant thermal impacts in the intertidal biota. In contrast, temperature appeared to cause significant mortality in the dominant plants and grazing and filter-feeding animals in HP-HW treatment sites. Observations of displacement and mortality for clams and mussels suggest that physical effects may be substantial in some cases. Of the types of treatment examined, dispersant and beach cleaner treatments appeared to be accompanied with the smallest number of significant changes in abundance; however, this conclusion is weak because the LP-WW wash accompanying chemical applications during the tests was sometimes less rigorous than when performed by itself. LP-WW treatment was accompanied by an intermediate level of changes whereas HP-HW treatment was accompanied with the highest percentage of changes, nearly all of which were decreases

  17. Assessing impacts of ionizing radiation on non-human biota: the ERICA tool

    International Nuclear Information System (INIS)

    Brown, Justin; Lilanda, Astrid; Hosseini, Ali; Alfonso, B.; Avila, R.; Beresford, N.A.; Proehl, G.; Ulanovsky, A.

    2008-01-01

    There have been significant developments in the last few years concerning methods to explicitly quantify impacts on the environment arising from exposure by ionising radiation. Central to the ERICA integrated approach is the quantification of environmental risk whereby data on environmental transfer and dosimetry are combined to provide a measure of exposure which is compared to exposure levels at which detrimental effects are known to occur. In view of the large data sets underpinning the assessment approach and the potential to introduce errors when performing numerous calculations manually, a supporting computer-based tool (the ERICA Tool) has been developed. The ERICA Tool is a computerised, flexible software system that has a structure based upon the ERICA Integrated Assessment tiered approach to assessing the radiological risk to biota. The user is guided through the assessment process, recording information and decisions as the assessment progresses. The tool allows the necessary calculations to be performed to estimate risks to selected biota. Tier 1 assessments use pre-calculated environmental media concentration limits to estimate risk quotients and require inputs in the form of media concentrations. At Tier 2 dose-rates are calculated but at this stage, the user is allowed to examine and edit most of the parameters used in the calculation. For Tier 3 assessments, the same flexibility as Tier 2 is allowed but assessments may be run probability if the underling parameter probability distribution functions are defined. Results from the tool can be put into context using incorporated data on dose-effects relationships and background dose-rates. (author)

  18. Recent changes in aquatic biota in subarctic Fennoscandia - the role of global and local environmental variables

    Science.gov (United States)

    Weckström, Jan; Leppänen, Jaakko; Sorvari, Sanna; Kaukolehto, Marjut; Weckström, Kaarina; Korhola, Atte

    2013-04-01

    The Arctic, representing a fifth of the earth's surface, is highly sensitive to the predicted future warming and it has indeed been warming up faster than most other regions. This makes the region critically important and highlights the need to investigate the earliest signals of global warming and its impacts on the arctic and subarctic aquatic ecosystems and their biota. It has been demonstrated that many Arctic freshwater ecosystems have already experienced dramatic and unpreceded regime shifts during the last ca. 150 years, primarily driven by climate warming. However, despite the indisputable impact of climate-related variables on freshwater ecosystems other, especially local-scale catchment related variables (e.g. geology, vegetation, human activities) may override the climate signal and become the primary factor in shaping the structure of aquatic ecosystems. Although many studies have contributed to an improved understanding of limnological and hydrobiological features of Artic and subarctic lakes, much information is still needed especially on the interaction between the biotic and abiotic components, i.e. on factors controlling the food web dynamics in these sensitive aquatic ecosystems. This is of special importance as these lakes are of great value in water storage, flood prevention, and maintenance of biodiversity, in addition to which they are vital resources for settlement patterns, food production, recreation, and tourism. In this study we compare the pre-industrial sediment assemblages of primary producers (diatoms and Pediastrum) and primary consumers (cladoceran and chironomids) with their modern assemblages (a top-bottom approach) from 50 subarctic Fennoscandian lakes. We will evaluate the recent regional pattern of changes in aquatic assemblages, and assess how coherent the lakes' responses are across the subarctic area. Moreover, the impact of global (e.g. climate, precipitation) and local (e.g. lake and its catchment characteristics) scale

  19. Nutrient density of beverages in relation to climate impact.

    Science.gov (United States)

    Smedman, Annika; Lindmark-Månsson, Helena; Drewnowski, Adam; Edman, Anna-Karin Modin

    2010-08-23

    The food chain contributes to a substantial part of greenhouse gas (GHG) emissions and growing evidence points to the urgent need to reduce GHGs emissions worldwide. Among suggestions were proposals to alter food consumption patterns by replacing animal foods with more plant-based foods. However, the nutritional dimensions of changing consumption patterns to lower GHG emissions still remains relatively unexplored. This study is the first to estimate the composite nutrient density, expressed as percentage of Nordic Nutrition Recommendations (NNR) for 21 essential nutrients, in relation to cost in GHG emissions of the production from a life cycle perspective, expressed in grams of CO(2)-equivalents, using an index called the Nutrient Density to Climate Impact (NDCI) index. The NDCI index was calculated for milk, soft drink, orange juice, beer, wine, bottled carbonated water, soy drink, and oat drink. Due to low-nutrient density, the NDCI index was 0 for carbonated water, soft drink, and beer and below 0.1 for red wine and oat drink. The NDCI index was similar for orange juice (0.28) and soy drink (0.25). Due to a very high-nutrient density, the NDCI index for milk was substantially higher (0.54) than for the other beverages. Future discussion on how changes in food consumption patterns might help avert climate change need to take both GHG emission and nutrient density of foods and beverages into account.

  20. Nutrient density of beverages in relation to climate impact

    Directory of Open Access Journals (Sweden)

    Annika Smedman

    2010-08-01

    Full Text Available The food chain contributes to a substantial part of greenhouse gas (GHG emissions and growing evidence points to the urgent need to reduce GHGs emissions worldwide. Among suggestions were proposals to alter food consumption patterns by replacing animal foods with more plant-based foods. However, the nutritional dimensions of changing consumption patterns to lower GHG emissions still remains relatively unexplored. This study is the first to estimate the composite nutrient density, expressed as percentage of Nordic Nutrition Recommendations (NNR for 21 essential nutrients, in relation to cost in GHG emissions of the production from a life cycle perspective, expressed in grams of CO2-equivalents, using an index called the Nutrient Density to Climate Impact (NDCI index. The NDCI index was calculated for milk, soft drink, orange juice, beer, wine, bottled carbonated water, soy drink, and oat drink. Due to low-nutrient density, the NDCI index was 0 for carbonated water, soft drink, and beer and below 0.1 for red wine and oat drink. The NDCI index was similar for orange juice (0.28 and soy drink (0.25. Due to a very high-nutrient density, the NDCI index for milk was substantially higher (0.54 than for the other beverages. Future discussion on how changes in food consumption patterns might help avert climate change need to take both GHG emission and nutrient density of foods and beverages into account.

  1. Interactions between above- and belowground biota : importance for small-scale vegetation mosaics in a grassland ecosystem

    NARCIS (Netherlands)

    Blomqvist, N.M.; Olff, H.; Blaauw, M.B.; Bongers, T.; Putten, van der W.H.

    2000-01-01

    Grasslands are often characterised by small-scale mosaics in plant community composition that contribute to their diversity. Although above- and belowground biota can both cause such mosaics, few studies have addressed their interacting effects. We studied multi-trophic interactions between

  2. Long-term and realistic global change manipulations had low impact on diversity of soil biota in temperate heathland

    DEFF Research Database (Denmark)

    Holmstrup, Martin; Damgaard, Christian; Schmidt, Inger K

    2017-01-01

    C:N ratio. After eight years of treatment, however, the CO2-increased litter C:N ratio did not influence the diversity in any of the four fauna groups. The number of significant correlations between treatments, food source quality, and soil biota diversities was reduced from six to three after two...

  3. Determination of polychlorinated terphenyls in aquatic biota and sediment with gas chromatography/mass spectrometry using negative chemical ionization.

    NARCIS (Netherlands)

    Wester, P.G.; de Boer, J.; Brinkman, U.A.T.

    1996-01-01

    Polychlorinated terphenyls (PCTs) have been determined in aquatic biota and sediments by gas chromatography/mass spectrometry using negative chemical ionization. The use of various methods of calculation is discussed. Total PCT concentrations expressed as A (Aroclor) 5442 equivalents ranged from

  4. Screes as important landscape structures for xeric and psychrophilic biota conservation and monitoring environmental change in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Zacharda, Miloslav; Boucníková, Eva

    Sup.1/2005, č. 24 (2005), s. 28-38 ISSN 1335-342X Institutional research plan: CEZ:AV0Z60870520 Keywords : scree * landscape diversity * biota * conservation * global change Subject RIV: EH - Ecology, Behaviour Impact factor: 0.085, year: 2005

  5. Description of Ethical Bio-Technology Assessment Tools for Agriculture and Food Production. Interim Report Ethical Bio-TA Tools

    NARCIS (Netherlands)

    Beekman, V.

    2004-01-01

    The objective of 'Ethical Bio-TA Tools' project is to develop and improve tools for the ethical assessment of new technologies in agriculture and food production in general and modern biotechnologies in particular. The developed tools need to be designed for various purposes and contexts. They

  6. Impacts on non-human biota from a generic geological disposal facility for radioactive waste: some key assessment issues

    International Nuclear Information System (INIS)

    Robinson, C A; Smith, K L; Norris, S

    2010-01-01

    This paper provides an overview of key issues associated with the application of currently available biota dose assessment methods to consideration of potential environmental impacts from geological disposal facilities. It explores philosophical, methodological and practical assessment issues and reviews the implications of test assessment results in the context of recent and on-going challenges and debates.

  7. Concentrations and trophic magnification of cyclic siloxanes in aquatic biota from the Western Basin of Lake Erie, Canada

    International Nuclear Information System (INIS)

    McGoldrick, Daryl J.; Chan, Cecilia; Drouillard, Ken G.; Keir, Michael J.; Clark, Mandi G.; Backus, Sean M.

    2014-01-01

    We examine the concentrations and food web biomagnification of three cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) using aquatic biota collected from Lake Erie. Concentrations of cVMS in biota were within the range reported for other studies of cVMS in aquatic biota. Trophic magnification factors (TMF) were assessed in various food web configurations to investigate the effects of food web structure. TMF estimates were highly dependent on the inclusion/exclusion of the organisms occupying the highest and lowest trophic levels and were >1 for D4 and D5, indicating biomagnification, in only 1 of the 5 food web configurations investigated and were <1 in the remaining 4 food web configurations. TMF estimates for PCB180 were also dependant on food web configuration, but did not correspond with those obtained for cVMS materials. These differences may be attributed to environmental exposure and/or lipid partitioning differences between PCB180 and cVMS. -- Highlights: • We investigated trophic magnification of siloxanes in aquatic biota from Lake Erie. • Trophic magnification estimates were variable and sensitive to food web structure. • Lipid partitioning of siloxanes and PCBs differ and may contribute to variability. -- Biomagnification estimates for siloxanes in Lake Erie are sensitive to food web structure, contaminant exposure pathways, and lipid partitioning differences between PCBs and siloxanes

  8. The effect of varying nitrogen and phosphorus availability on nutrient use by Larrea tridentata, a desert evergreen shrub.

    Science.gov (United States)

    Lajtha, Kate; Klein, Melanie

    1988-04-01

    In a phytotron study of the effects of nitrogen and phosphorus supply ratio on nutrient uptake and use by Larrea tridentata, seedlings responded to increases in N and P availability with increases in leaf size, total biomass, and leaf nutrient concentration, and with decreases in root: shoot ratio. N and P use efficiency decreased with increasing N and P availability, respectively, but increased with increasing availability of the other nutrient, suggesting that Larrea responds both to the absolute and to the relative availability of limiting nutrients. Absolute amounts of N and P resorption, as well as N and P resorption efficiencies did not demonstrate a significant trend with nutrient availability, and there was no evidence of significant interactions between the two nutrients. More studies of the effects of nutrient interactions in the cycling and use of nutrients by different plant species are needed before more general conclusions can be drawn.

  9. Observation of radionuclides in marine biota off the coast of Fukushima prefecture after TEPCO's Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    Aono, Tatsuo; Ito, Yukari; Kanda, Jyota; Ishimaru, Takashi; Saotome, Tadahiro; Mizuno, Takuji; Igarashi, Satoshi

    2012-01-01

    Monitoring and surveying radioactivity in seawater and biota in the marine environment off the coast of Fukushima prefecture in the Pacific are important for understanding the dispersion of artificial radionuclides after TEPCO's Fukushima Daiichi Nuclear Power Plant (F1NPP) accident. Marine biota were collected in the coastal area of Fukushima prefecture after this accident due to investigate the activities of 134 Cs, 137 Cs, and 110m Ag in marine biota, including not only fish and shellfish but also benthos. It is well known that 108m Ag, one of the radioactive isotopes of Ag, was observed in some kinds of squid and octopus before this accident. As the results, 110m Ag was observed in many kinds of marine biota off the coastal area of Fukushima. It is suggested that rapid change in the radioactivities in seawater, resuspension of particles from sediments and food chain effects led to high radionuclide activities in marine biota after this accident. (author)

  10. Advances in the understanding of nutrient dynamics and management in UK agriculture

    International Nuclear Information System (INIS)

    Dungait, Jennifer A.J.; Cardenas, Laura M.; Blackwell, Martin S.A.; Wu, Lianhai; Withers, Paul J.A.; Chadwick, David R.; Bol, Roland; Murray, Philip J.; Macdonald, Andrew J.; Whitmore, Andrew P.; Goulding, Keith W.T.

    2012-01-01

    Current research on macronutrient cycling in UK agricultural systems aims to optimise soil and nutrient management for improved agricultural production and minimise effects on the environment and provision of ecosystem services. Nutrient use inefficiencies can cause environmental pollution through the release of greenhouse gases into the atmosphere and of soluble and particulate forms of N, P and carbon (C) in leachate and run-off into watercourses. Improving nutrient use efficiencies in agriculture calls for the development of sustainable nutrient management strategies: more efficient use of mineral fertilisers, increased recovery and recycling of waste nutrients, and, better exploitation of the substantial inorganic and organic reserves of nutrients in the soil. Long-term field experimentation in the UK has provided key knowledge of the main nutrient transformations in agricultural soils. Emerging analytical technologies, especially stable isotope labelling, that better characterise macronutrient forms and bioavailability and improve the quantification of the complex relationships between the macronutrients in soils at the molecular scale, are augmenting this knowledge by revealing the underlying processes. The challenge for the future is to determine the relationships between the dynamics of N, P and C across scales, which will require both new modelling approaches and integrated approaches to macronutrient cycling. -- Highlights: ► Major advances in the knowledge of macronutrient cycling in agricultural soils are reviewed in the context of management. ► Novel analytical techniques and innovative modelling approaches that enhance understanding of nutrient cycling are explored. ► Knowledge gaps are identified, and the potential to improve comprehension of the integrated nutrient cycles is considered.

  11. Abiotic and biotic controls over biogeochemical cycles in drylands: Insights from climate change and nitrogen deposition experiments on the Colorado Plateau

    Science.gov (United States)

    Reed, S.; Ferrenberg, S.; Tucker, C.; Rutherford, W. A.; Wertin, T. M.; McHugh, T. A.; Morrissey, E.; Kuske, C.; Mueller, R.; Belnap, J.

    2016-12-01

    As for all ecosystems, biogeochemical cycling in drylands represents numerous intricate connections between biotic and abiotic controls. However, patterns of many fundamental ecosystem processes that generally hold across global gradients fall apart at the arid and semiarid end of the spectrum, and data point to an exceptionally strong role for abiotic controls in explaining these patterns. Further, there are multiple dryland characteristics - such as extreme aridity and high UV radiation, as well as specialized biological communities - which can point to a conclusion that "drylands are different". Indeed, drylands are often characterized by their harsh environment, by the diverse classes of biota representing a range of traits aimed at surviving such harsh conditions, and, more recently, by the suggestion of dramatic biotic responses to seemingly subtle changes in abiotic factors. In this talk, we will explore a range of biotic and abiotic controls over fundamental biogeochemical cycling in drylands using data from a suite of manipulation experiments on the Colorado Plateau, USA. We will present results from field treatments that speak to the effects of increasing temperature, altered precipitation regimes, increased nitrogen availability via deposition, and the effects of altered litterfall inputs. Biogeochemical processes we explore will include plant photosynthesis, soil photosynthesis and respiration (with a focus on biological soil crusts), litter decomposition, and nutrient cycling. In addition, we will assess how treatments alter dryland community composition, as well as the resultant feedbacks of community shifts to environmental change. Taken together we will use these diverse datasets to ask questions about what makes drylands different or, instead, if a holistic joining of biotic and abiotic perspectives suggests they are not so different after all. These data will not only lend insight into the partitioning of and balance between biotic and abiotic

  12. Decomposition, nutrient release patterns and nutrient fluxes from ...

    African Journals Online (AJOL)

    Studies were conducted on leaf litter fall, decomposition, nutrient release patterns and nutrient fluxes of Akyaakrom (AS) and Dopiri (DS) secondary forest leaf litter in Dwinyama watershed. Leaf litter production were 9.1 and 6.8 t ha-1 y-1 in AS and 8.9 and 6.5 t ha-1 y-1 in DS in the 1st (September 1998-August 1999) and ...

  13. Screening of perfluorinated compounds in water, sediment and biota of the Llobregat River basin (NE Spain)

    Science.gov (United States)

    Campo, Julian; Perez, Francisca; Pico, Yolanda; Farre, Marinella; Barcelo, Damia; Andreu, Vicente

    2014-05-01

    PFCs present significant thermal and chemical stability being persistent in the environment, where they can bio-accumulate and adversely affect humans and wildlife (Llorca et al., 2012). Human exposure to PFCs is of concern since PFCs tend to be associated with fatty acid binding proteins in the liver or albumin proteins in blood, and have been detected in human serum, urine, saliva, seminal plasma and breast milk (Sundstrom et al., 2011). This study is aimed at the screening of 21 perfluorinated compounds (PFCs) in environmental samples by high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS). The main objective is to identify target compounds at low levels in water, sediments and biota of the Llobregat River (2010), second longest river in Catalonia and one of Barcelona's major drinking water resources. PFCs were extracted from water samples by Solid Phase Extraction (SPE); from sediment by ultrasonication with acidified methanol followed by an off-line SPE procedure (Picó et al., 2012), and from biota (fish) with alkaline digestion, clean-up by TurboFlow™ on line technology coupled to LC-MS/MS (Llorca et al., 2012). The limits of detection (LODs) and limits of quantification (LOQs) of the method were calculated by analysis of spiked river water, sediment, and biota with minimum concentrations of each individual compound at a signal-to-noise ratio of 3 and 10, respectively. The LODs and LOQs of the method in river water ranged between 0.004 and 0.8 ng L-1 and between 0.01 and 2 ng L-1, respectively. In sediment LODs were 0.013-2.667 ng g-1 dry weight (dw) and LOQs were 0.04-8 ng g-1 dw, meanwhile in biota these were 0.006-0.7 pg μL-1 and 0.02-2.26 pg μL-1, respectively. Recoveries ranged between 65% and 102% for all target compounds. The method was applied to study the spatial distribution of these compounds in the Llobregat River basin. For this, a total of 40 samples were analysed (14 water, 14 sediments, 12 fishes). Of the 21 target

  14. Biogeochemical cycling of radionuclides in the environment

    International Nuclear Information System (INIS)

    Livens, F.R.

    1990-01-01

    The biogeochemical cycling of radionuclides with other components such as nutrients around ecosystems is discussed. In particular the behaviour of cesium in freshwater ecosystems since the Chernobyl accident and the behaviour of technetium in the form of pertechnetate anions, TcO 4 , in marine ecosystems is considered. (UK)

  15. Monitoring TASCC Injections Using A Field-Ready Wet Chemistry Nutrient Autoanalyzer

    Science.gov (United States)

    Snyder, L. E.; Herstand, M. R.; Bowden, W. B.

    2011-12-01

    Quantification of nutrient cycling and transport (spiraling) in stream systems is a fundamental component of stream ecology. Additions of isotopic tracer and bulk inorganic nutrient to streams have been frequently used to evaluate nutrient transfer between ecosystem compartments and nutrient uptake estimation, respectively. The Tracer Addition for Spiraling Curve Characterization (TASCC) methodology of Covino et al. (2010) instantaneously and simultaneously adds conservative and biologically active tracers to a stream system to quantify nutrient uptake metrics. In this method, comparing the ratio of mass of nutrient and conservative solute recovered in each sample throughout a breakthrough curve to that of the injectate, a distribution of spiraling metrics is calculated across a range of nutrient concentrations. This distribution across concentrations allows for both a robust estimation of ambient spiraling parameters by regression techniques, and comparison with uptake kinetic models. We tested a unique sampling strategy for TASCC injections in which samples were taken manually throughout the nutrient breakthrough curves while, simultaneously, continuously monitoring with a field-ready wet chemistry autoanalyzer. The autoanalyzer was programmed to measure concentrations of nitrate, phosphate and ammonium at the rate of one measurement per second throughout each experiment. Utilization of an autoanalyzer in the field during the experiment results in the return of several thousand additional nutrient data points when compared with manual sampling. This technique, then, allows for a deeper understanding and more statistically robust estimation of stream nutrient spiraling parameters.

  16. Root morphology and mycorrhizal symbioses together shape nutrient foraging strategies of temperate trees.

    Science.gov (United States)

    Chen, Weile; Koide, Roger T; Adams, Thomas S; DeForest, Jared L; Cheng, Lei; Eissenstat, David M

    2016-08-02

    Photosynthesis by leaves and acquisition of water and minerals by roots are required for plant growth, which is a key component of many ecosystem functions. Although the role of leaf functional traits in photosynthesis is generally well understood, the relationship of root functional traits to nutrient uptake is not. In particular, predictions of nutrient acquisition strategies from specific root traits are often vague. Roots of nearly all plants cooperate with mycorrhizal fungi in nutrient acquisition. Most tree species form symbioses with either arbuscular mycorrhizal (AM) or ectomycorrhizal (EM) fungi. Nutrients are distributed heterogeneously in the soil, and nutrient-rich "hotspots" can be a key source for plants. Thus, predicting the foraging strategies that enable mycorrhizal root systems to exploit these hotspots can be critical to the understanding of plant nutrition and ecosystem carbon and nutrient cycling. Here, we show that in 13 sympatric temperate tree species, when nutrient availability is patchy, thinner root species alter their foraging to exploit patches, whereas thicker root species do not. Moreover, there appear to be two distinct pathways by which thinner root tree species enhance foraging in nutrient-rich patches: AM trees produce more roots, whereas EM trees produce more mycorrhizal fungal hyphae. Our results indicate that strategies of nutrient foraging are complementary among tree species with contrasting mycorrhiza types and root morphologies, and that predictable relationships between below-ground traits and nutrient acquisition emerge only when both roots and mycorrhizal fungi are considered together.

  17. Biomass and nutrient distribution and their return of Casuarina equisetifolia inoculated with biofertilizers in farm land

    Energy Technology Data Exchange (ETDEWEB)

    Rajendran, K.; Devaraj, P. [Institute of Forest Genetics and Tree Breeding, Coimbatore (India)

    2004-03-01

    An experiment was conducted to study the productivity, nutrient distribution and nutrient cycling of Casuarina equisetifolia Forst in farm forestry. Seedlings inoculated with different biofertilizers such as Azospirillum, Phosphobacterium, AM fungi and Frankia along with their combinations were planted in farmland. Growth, biomass, nutrient distribution, nutrient uptake and nutrient-return through litter were estimated 24 months after planting by harvesting the plant. The height of the tree is ranged from 9.87 to 11.90 m and the girth at breast height (gbh) is ranged from 16.8 to 23.2 cm. The maximum height, gbh and total biomass were obtained in the combined application of Azospirillum, Phosphobacterium, AM and Frankia. The combination of AM + Frankia among double inoculation, and in combination of Azospirillum, AM and Frankia in triple inoculation also proved to be the best treatment in promoting the significant total height, gbh and total biomass production. Better nutrient uptake was estimated in combined inoculation of Azospirillum + Phosphobacterium + AM + Frankia followed by Azospirillum + AM + Frankia in respect of the nutrients such as N, P, K, Ca and Mg. The nutrient concentration was distributed in the order of needle > branch > root nodule > twig > stem > root. Nutrient return in field condition showed the maximum nutrient-return through litter in combination with Azospirillum + Phosphobacterium + AM + Frankia inoculated trees. (author)

  18. Root morphology and mycorrhizal symbioses together shape nutrient foraging strategies of temperate trees

    Science.gov (United States)

    Chen, Weile; Koide, Roger T.; Adams, Thomas S.; DeForest, Jared L.; Cheng, Lei; Eissenstat, David M.

    2016-01-01

    Photosynthesis by leaves and acquisition of water and minerals by roots are required for plant growth, which is a key component of many ecosystem functions. Although the role of leaf functional traits in photosynthesis is generally well understood, the relationship of root functional traits to nutrient uptake is not. In particular, predictions of nutrient acquisition strategies from specific root traits are often vague. Roots of nearly all plants cooperate with mycorrhizal fungi in nutrient acquisition. Most tree species form symbioses with either arbuscular mycorrhizal (AM) or ectomycorrhizal (EM) fungi. Nutrients are distributed heterogeneously in the soil, and nutrient-rich “hotspots” can be a key source for plants. Thus, predicting the foraging strategies that enable mycorrhizal root systems to exploit these hotspots can be critical to the understanding of plant nutrition and ecosystem carbon and nutrient cycling. Here, we show that in 13 sympatric temperate tree species, when nutrient availability is patchy, thinner root species alter their foraging to exploit patches, whereas thicker root species do not. Moreover, there appear to be two distinct pathways by which thinner root tree species enhance foraging in nutrient-rich patches: AM trees produce more roots, whereas EM trees produce more mycorrhizal fungal hyphae. Our results indicate that strategies of nutrient foraging are complementary among tree species with contrasting mycorrhiza types and root morphologies, and that predictable relationships between below-ground traits and nutrient acquisition emerge only when both roots and mycorrhizal fungi are considered together. PMID:27432986

  19. Nutrient and Coliform Loading (NCL)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is a database of available fecal coliform bacteria, fecal streptococci bacteria, and nutrient loading data. Loading for contaminants other than fecal coliform...

  20. Nutrient imbalance in Norway spruce

    International Nuclear Information System (INIS)

    Thelin, Gunnar

    2000-11-01

    The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met. The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable. Countermeasures are needed in order to maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the need for

  1. Nutrient imbalance in Norway spruce

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar

    2000-11-01

    The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met. The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable. Countermeasures are needed in order to maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the need for

  2. Happy Cycling

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte; Nielsen, Tom

    2013-01-01

    og Interaktions Design, Aarhus Universitet under opgave teamet: ”Happy Cycling City – Aarhus”. Udfordringen i studieopgaven var at vise nye attraktive løsningsmuligheder i forhold til cyklens og cyklismens integration i byrum samt at påpege relationen mellem design og overordnede diskussioner af...

  3. Glacial cycles

    DEFF Research Database (Denmark)

    Kaufmann, R. K.; Juselius, Katarina

    We use a statistical model, the cointegrated vector autoregressive model, to assess the degree to which variations in Earth's orbit and endogenous climate dynamics can be used to simulate glacial cycles during the late Quaternary (390 kyr-present). To do so, we estimate models of varying complexi...

  4. CYCLE CONTROL

    African Journals Online (AJOL)

    changed to gestodene. Although large- scale comparative trials are needed to confirm this finding, evidence suggests that cycle control with gestodene is better than for monophasic preparations containing desogestrel, norgestimate or levonorgestrel,10 as well as for levonorg- estrel-or norethisterone-containing triphasics.

  5. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    2008-01-01

    Roč. 63, č. 1 (2008), s. 308-327 ISSN 0899-8256 Institutional research plan: CEZ:AV0Z70850503 Keywords : global games * coordination * crises * cycles and fluctuations Subject RIV: AH - Economics Impact factor: 1.333, year: 2008

  6. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    -, č. 274 (2005), s. 1-26 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : coordination * crises * cycles and fluctuations Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp274.pdf

  7. Birth of a biome: insights into the assembly and maintenance of the Australian arid zone biota.

    Science.gov (United States)

    Byrne, M; Yeates, D K; Joseph, L; Kearney, M; Bowler, J; Williams, M A J; Cooper, S; Donnellan, S C; Keogh, J S; Leys, R; Melville, J; Murphy, D J; Porch, N; Wyrwoll, K-H

    2008-10-01

    The integration of phylogenetics, phylogeography and palaeoenvironmental studies is providing major insights into the historical forces that have shaped the Earth's biomes. Yet our present view is biased towards arctic and temperate/tropical forest regions, with very little focus on the extensive arid regions of the planet. The Australian arid zone is one of the largest desert landform systems in the world, with a unique, diverse and relatively well-studied biota. With foci on palaeoenvironmental and molecular data, we here review what is known about the assembly and maintenance of this biome in the context of its physical history, and in comparison with other mesic biomes. Aridification of Australia began in the Mid-Miocene, around 15 million years, but fully arid landforms in central Australia appeared much later, around 1-4 million years. Dated molecular phylogenies of diverse taxa show the deepest divergences of arid-adapted taxa from the Mid-Miocene, consistent with the onset of desiccation. There is evidence of arid-adapted taxa evolving from mesic-adapted ancestors, and also of speciation within the arid zone. There is no evidence for an increase in speciation rate during the Pleistocene, and most arid-zone species lineages date to the Pliocene or earlier. The last 0.8 million years have seen major fluctuations of the arid zone, with large areas covered by mobile sand dunes during glacial maxima. Some large, vagile taxa show patterns of recent expansion and migration throughout the arid zone, in parallel with the ice sheet-imposed range shifts in Northern Hemisphere taxa. Yet other taxa show high lineage diversity and strong phylogeographical structure, indicating persistence in multiple localised refugia over several glacial maxima. Similar to the Northern Hemisphere, Pleistocene range shifts have produced suture zones, creating the opportunity for diversification and speciation through hybridisation, polyploidy and parthenogenesis. This review highlights

  8. Investigation of metal toxicity to tropical biota. Recommendations for revision of Australian water quality guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Marchich, S. [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). Environment Div.; Camilleri, C. [Environmental Research Inst of the Supervising Scientist, Jabiru, NT (Australia)

    1997-12-31

    The specific objectives of this study were to: review available data on the toxicity of metals to aquatic biota in tropical Australia; identify metals considered to be priority toxicants to aquatic biota in tropical Australia; and employ previously developed toxicity testing protocols for two tropical freshwater species to obtain preliminary toxicity data for two priority metals. From the literature review, it was concluded that insufficient metal toxicity data exist for Australian tropical species. Data were absent for a range of metals (eg Ag, As, Al, Cr, Hg, Ni, Sb and Se) listed in the current Australian water quality guidelines. Aluminium, Cd, Co, Cu, Ni, Mn, Pb, U, V and Zn were identified as priority metals of potential ecotoxicological concern in aquatic ecosystems of tropical Australia, largely as a consequence of mining activities, but also from urban impacts. Instead of testing the toxicity of the priority metals for which data do not currently exist (ie Al, Co, Ni and V), it was deemed more important to conduct further experimental work on Cu and U, in the context of elucidating the relatively high variability in the toxic response of these two metals. As a result, Cu and U were selected and toxicity tests conducted using two tropical freshwater species (green hydra (Hydra viridissima) and gudgeon fish (Mogurnda mogurnda)) from the Australian wet/dry tropics using test protocols designed to maximise the greatest sensitivity of metal response in the shortest period of time. Hydra viridissima was about eight times more sensitive to Cu than U, whereas M. mogurnda was about twenty times more sensitive. Once differences between the sublethal and lethal endpoints of the two organisms were corrected by statistical extrapolation, H. viridissima was approximately seven times more sensitive than M. mogurnda to U, but only about three times more sensitive to Cu. Both species were more sensitive to Cu than U. These results are generally consistent with those from

  9. Investigation of metal toxicity to tropical biota. Recommendations for revision of Australian water quality guidelines

    International Nuclear Information System (INIS)

    Marchich, S.

    1997-01-01

    The specific objectives of this study were to: review available data on the toxicity of metals to aquatic biota in tropical Australia; identify metals considered to be priority toxicants to aquatic biota in tropical Australia; and employ previously developed toxicity testing protocols for two tropical freshwater species to obtain preliminary toxicity data for two priority metals. From the literature review, it was concluded that insufficient metal toxicity data exist for Australian tropical species. Data were absent for a range of metals (eg Ag, As, Al, Cr, Hg, Ni, Sb and Se) listed in the current Australian water quality guidelines. Aluminium, Cd, Co, Cu, Ni, Mn, Pb, U, V and Zn were identified as priority metals of potential ecotoxicological concern in aquatic ecosystems of tropical Australia, largely as a consequence of mining activities, but also from urban impacts. Instead of testing the toxicity of the priority metals for which data do not currently exist (ie Al, Co, Ni and V), it was deemed more important to conduct further experimental work on Cu and U, in the context of elucidating the relatively high variability in the toxic response of these two metals. As a result, Cu and U were selected and toxicity tests conducted using two tropical freshwater species (green hydra (Hydra viridissima) and gudgeon fish (Mogurnda mogurnda)) from the Australian wet/dry tropics using test protocols designed to maximise the greatest sensitivity of metal response in the shortest period of time. Hydra viridissima was about eight times more sensitive to Cu than U, whereas M. mogurnda was about twenty times more sensitive. Once differences between the sublethal and lethal endpoints of the two organisms were corrected by statistical extrapolation, H. viridissima was approximately seven times more sensitive than M. mogurnda to U, but only about three times more sensitive to Cu. Both species were more sensitive to Cu than U. These results are generally consistent with those from

  10. EarthShape: A Strategy for Investigating the Role of Biota on Surface Processes

    Science.gov (United States)

    Übernickel, Kirstin; Ehlers, Todd Alan; von Blanckenburg, Friedhelm; Paulino, Leandro

    2017-04-01

    EarthShape - "Earth surface shaping by biota" is a 6-year priority research program funded by the German science foundation (DFG-SPP 1803) that performs soil- and landscape-scale critical zone research at 4 locations along a climate gradient in Chile, South America. The program is in its first year and involves an interdisciplinary collaboration between geologists, geomorphologists, ecologists, soil scientists, microbiologists, geophysicists, geochemists, hydrogeologists and climatologists including 18 German and 8 Chilean institutions. EarthShape is composed of 4 research clusters representing the process chain from weathering of substrate to deposition of eroded material. Cluster 1 explores micro-biota as the "weathering engine". Investigations in this cluster quantify different mechanisms of biogenic weathering whereby plants, fungi, and bacteria interact with rock in the production of soil. Cluster 2 explores bio-mediated redistribution of material within the weathering zone. Studies in this cluster focus on soil catenas along hill slope profiles to investigate the modification of matter along its transport path. Cluster 3 explores biotic modulation of erosion and sediment routing at the catchment scale. Investigations in this cluster explore the effects of vegetation cover on solute and sediment transport from hill slopes to the channel network. Cluster 4 explores the depositional legacy of coupled biogenic and Earth surface systems. This cluster investigates records of vegetation-land surface interactions in different depositional settings. A final component of EarthShape lies in the integration of results from these 4 clusters using numerical models to bridging between the diverse times scales used by different disciplines. The Chilean Coastal Cordillera between 25° and 40°S was selected to carry out this research because its north-south orientation captures a large ecological and climate gradient. This gradient ranges from hyper-arid (Atacama desert) to

  11. Uptake, turnover and distribution of chlorinated fatty acids in aquatic biota

    Energy Technology Data Exchange (ETDEWEB)

    Bjoern, Helena

    1999-09-01

    Chlorinated fatty acids (CIFAs) are the major contributors of extractable, organically bound chlorine in fish lipids. A known anthropogenic source of CIFAs is chlorine bleached pulp production. Additional anthropogenic sources may exist, e.g., chlorine-containing discharge from industrial and household waste and they may also occur naturally. CIFAs have a wide geographic distribution. They have, for instance, been identified in fish both from Alaskan and Scandinavian waters. In toxicological studies of CIFAs, the most pronounced effects have been found in reproductive related processes. CIFAs have also been shown to disrupt cell membrane functions. The present study was carried out to further characterise the ecotoxicological properties of CIFAs and their presence in biota. To investigate the biological stability of CIFAs, two experiments were carried out using radiolabelled chlorinated and non-chlorinated fatty acids. In both experiments, CIFAs were taken up from food by fish and assimilated to lipids. From the first experiment it was concluded that the chlorinated fatty acid investigated was turned over in the fish to a lower degree than the non-chlorinated analogue. In the second experiment, the transfer of a chlorinated fatty acid was followed over several trophic levels and the chlorinated fatty acid was transferred to the highest trophic level. In samples with differing loads of persistent organic pollutants (POPs) from both fish and marine mammals, high concentrations and diversity of CIFAs were detected. This was also observed in samples with low POP concentration. Chlorohydroxy fatty acids made up a considerable portion of the CIFAs in certain samples, both from limnic fish and marine mammals. CIFAs in fish were found to be bound in complex lipids such as triacylglycerols (storage lipids) and phospholipids, as well as in acyl sterols (membrane lipids). In the marine mammals investigated, high concentrations of CIFAs were mainly bound in phospholipids. If

  12. Using stable isotope analysis to determine the contribution of naturally occurring pond biota and supplementary feed to the diet of farmed Australian freshwater crayfish, redclaw (Cherax quadricarinatus

    Directory of Open Access Journals (Sweden)

    Melissa K. Joyce

    2015-12-01

    Full Text Available Abstract Nutritional requirements of redclaw (Cherax quadricarinatus farmed in Australia are poorly understood and little is known on what is actively being consumed in semi-intensive pond culture. In this study the isotopic signatures of δ13C and δ15N of potential food sources were analysed with a multi-source mixing model to determine the extent of their contribution to the diet of farmed redclaw. Four commercial redclaw farms in North Queensland, Australia (Mareeba, Biboorha, Wondecla and Topaz were sampled for naturally occurring pond organisms and commonly used supplemental feed such as raw corn, soybean, lupin, commercial redclaw, and chicken feed. Both naturally occurring pond biota and supplemental feed contribute to the tissue composition of redclaw to some degree. However, the contribution varies with the type of feed and availability of natural sources, for example plant material at Topaz Farm was a greater contributor with 43.9 ± 19.5 % compared to supplementary sources raw corn 8.20 ± 3.10 and lupin 1.60 ± 1.70 %. Moreover, some supplemental feeds provided a direct nutrient source for primary pond productivity; contribution of the redclaw pellet to zoo- and phytoplankton at Wondecla Farm was 83.1 ± 6.50 and 50.0 ± 9.50 %, respectively, with similarly high values for chicken feed at Biboorha Farm of 72.6 ± 4.70 and 83.4 ± 6.90 %. The cost effectiveness of such feeds needs to be questioned if these are not being consumed and utilised directly. Providing a species-specific formulated feed with improved water stability would enhance production reliability and facilitate growth within the industry.

  13. Nutrient ratios as a tracer and driver of ocean biogeochemistry.

    Science.gov (United States)

    Deutsch, Curtis; Weber, Thomas

    2012-01-01

    Microbial life in the ocean contains immense taxonomic and physiological diversity, yet its collective activity yields global cycles of the major biolimiting elements N and P that are tightly linked. Moreover, the availability of N and P in seawater is closely matched to the metabolic demands of "average" plankton, as if plankton composition and the oceanic nutrient reservoirs were mutually influenced. These simple observations have broad implications for the function of nutrient cycles within the Earth system, which can operate either as a biological homeostat that buffers ocean fertility against large changes or as an amplifier of climate perturbations, by alleviating or exacerbating the nutrient limitation of biological productivity and ocean C storage. A mechanistic understanding of these observations and dynamics must draw upon diverse fields, from physiology and evolution to physical oceanography and paleoceanography, and must account for processes spanning a wide range of spatial and temporal scales. Here we summarize this understanding from the perspective of the nutrient distributions themselves and their changes over time. We offer a synthesis view in which ocean circulation communicates the resource constraints of stoichiometrically distinct planktonic biomes across large spatial scales, allowing geochemical constancy to emerge from rich biological diversity.

  14. Radiation dose to human and non-human biota in the republic of Korea resulting from the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Keum, Dong Kwon; Jun, In; Lim, Kwang Muk; Choi, Yong Ho

    2013-01-01

    This paper describes the radiation doses to human and non-human biota in the Republic of Korea, as a result of the Fukushima nuclear accident. By using the measured airborne activity and ground deposition, the effective and thyroid doses of five human age groups (infant, 5 years, 10 years, 15 years and adult) were estimated by the ECOSYS code, and the whole body absorbed dose rate of the eight Korean reference animals and plants (RAPs) was estimated by the K-BIOTA (the Korean computer code to assess the risk of radioactivity to wildlife). The first-year effective and thyroid human doses ranged from 5.7E-5 mSv in the infant group to 2.0E-4 mSv in the 5 years group, and from 5.0E-4 mSv in the infant group to 3.4E-3 mSv in the 5 years group, respectively. The life-time (70 years) effective and thyroid human doses ranged from 1.5E-4 mSv in the infant group to 3.0E-4 mSv in the 5 years group, and from 6.0E-4 mSv in the infant group to 3.5E-3 mSv in the 5 years group, respectively. The estimated maximum whole body absorbed dose rate to the Korean RAPs was 6.7E-7 mGy/d for a snake living in soil (terrestrial biota), and 2.0E-5 mGy/d for freshwater fish (aquatic biota), both of which were far less than the generic dose criteria to protect biota from ionizing radiation. Also, the screening level assessment for ERICA's (Environmental Risks from Ionizing Contaminants: Assessments and management) limiting organisms showed that the risk quotient (RQ) for the estimated maximum soil and water activity was significantly less than unity for both the terrestrial and freshwater organisms. Conclusively, the radiological risk of the radioactivity released into the environment by the Fukushima nuclear accident to the public and the non-human biota in the republic of Korea is considered negligible.

  15. Parasite infection alters nitrogen cycling at the ecosystem scale.

    Science.gov (United States)

    Mischler, John; Johnson, Pieter T J; McKenzie, Valerie J; Townsend, Alan R

    2016-05-01

    Despite growing evidence that parasites often alter nutrient flows through their hosts and can comprise a substantial amount of biomass in many systems, whether endemic parasites influence ecosystem nutrient cycling, and which nutrient pathways may be important, remains conjectural. A framework to evaluate how endemic parasites alter nutrient cycling across varied ecosystems requires an understanding of the following: (i) parasite effects on host nutrient excretion; (ii) ecosystem nutrient limitation; (iii) effects of parasite abundance, host density, host functional role and host excretion rate on nutrient flows; and (iv) how this infection-induced nutrient flux compares to other pools and fluxes. Pathogens that significantly increase the availability of a limiting nutrient within an ecosystem should produce a measurable ecosystem-scale response. Here, we combined field-derived estimates of trematode parasite infections in aquatic snails with measurements of snail excretion and tissue stoichiometry to show that parasites are capable of altering nutrient excretion in their intermediate host snails (dominant grazers). We integrated laboratory measurements of host nitrogen excretion with field-based estimates of infection in an ecosystem model and compared these fluxes to other pools and fluxes of nitrogen as measured in the field. Eighteen nitrogen-limited ponds were examined to determine whether infection had a measurable effect on ecosystem-scale nitrogen cycling. Because of their low nitrogen content and high demand for host carbon, parasites accelerated the rate at which infected hosts excreted nitrogen to the water column in a dose-response manner, thereby shifting nutrient stoichiometry and availability at the ecosystem scale. Infection-enhanced fluxes of dissolved inorganic nitrogen were similar to other commonly important environmental sources of bioavailable nitrogen to the system. Additional field measurements within nitrogen-limited ponds indicated that

  16. How to Determine Energy of Wood from Nutrient Analysis?

    OpenAIRE

    Bilot , Nicolas; Saint Andre , Laurent ,; Rogaume , Yann; Fournier , Meriem; Dupont , Capucine; Deleuze , Christine

    2014-01-01

    International audience; In the context of increasing energy demand, forest timber residues and leaves are a potential resource for fuel. How renewable are these resources? What are their qualities as a fuel? These issues can be answered through parallel works in two research fields: forest sciences considering nutrients cycles between plants and soil and growth and yield dynamics of the trees, and energy sciences considering the qualities of fuel such as heating value, and ash content. This i...

  17. Precipitation controls on nutrient budgets in subtropical and tropical forests and the implications under changing climate

    Science.gov (United States)

    Chang, Chung-Te; Wang, Lih-Jih; Huang, Chuan, Jr.; Liu, Chiung-Pin; Wang, Chiao-Ping; Lin, Neng-Huei; Wang, Lixin; Lin, Teng-Chiu

    2017-05-01

    Biological, geological and hydrological drivers collectively control forest biogeochemical cycling. However, based on a close examination of recent literature, we argue that the role of hydrological control particularly precipitation on nutrient budgets is significantly underestimated in subtropical and tropical forests, hindering our predictions of future forest nutrient status under a changing climate in these systems. To test this hypothesis, we analyzed two decades of monthly nutrient input and output data in precipitation and streamwater from a subtropical forested watershed in Taiwan, one of the few sites that has long-term nutrient input-output data in the tropics and subtropics. The results showed that monthly input and output of all ions and budgets (output - input) of most ions were positively correlated with precipitation quantity and there was a surprisingly greater net ion export during the wet growing season, indicating strong precipitation control on the nutrient budget. The strong precipitation control is also supported by the divergence of acidic precipitation and near neutral acidity of streamwater, with the former being independent from precipitation quantity but the latter being positively related to precipitation quantity. An additional synthesis of annual precipitation quantity and nutrient budgets of 32 forests across the globe showed a strong correlation between precipitation quantity and nutrient output-input budget, indicating that strong precipitation control is ubiquitous at the global scale and is particularly important in the humid tropical and subtropical forests. Our results imply that climate change could directly affect ecosystem nutrient cycling in the tropics through changes in precipitation pattern and amount.

  18. Phytomass production and nutrient accumulation by green manure species

    Directory of Open Access Journals (Sweden)

    José Carlos Soares Mangaravite

    2014-10-01

    Full Text Available Green manuring is recognized as a viable alternative to improve nutrient cycling in soils. The aim of this study was to evaluate the phytomass production and nutrient accumulation in shoots of the summer green manures jack bean [Canavalia ensiformis (L. DC.], dwarf pigeon pea (Cajanus cajanvar var. Flavus DC., dwarf mucuna [Mucuna deeringiana (Bort Merr] and sunn hemp (Crotalaria juncea L., under nitrogen fertilization and/or inoculation with N-fixing bacteria. A split plot design was arranged with the four Fabaceae species as main plots and nitrogen fertilization (with and without and inoculation with diazotrophic bacteria (with and without as the subplots, in a 2² factorial. The experiment was arranged as a randomized complete block design with four replications. In the conditions of this trial, the sunn hemp had the highest production of shoot phytomass (12.4 Mg ha-1 and nutrient accumulation, while the dwarf mucuna had the lowest production of shoot phytomass (3.9 Mg ha-1 and nutrient accumulation. The results showed no effect of nitrogen fertilization or inoculation with N-fixing bacteria on the production of shoot phytomass and nutrient accumulation, except for inoculation without nitrogen fertilization, resulting in greater P accumulation (p <0.05 in the sunn hemp and greater Zn and Mn accumulation in the dwarf mucuna. These findings indicate that N fertilization or inoculation with N2-fixing bacteria for Fabaceae are low efficiency practices in the edaphoclimatic conditions of this study.

  19. Soil Nutrient Stocks in Sub-Saharan Africa: Modeling Soil Nutrients Using Machine Learning

    Science.gov (United States)

    Cooper, M. W.; Hengl, T.; Shepherd, K.; Heuvelink, G. B. M.

    2017-12-01

    We present the results of our work modeling 15 target soil nutrients at 250 meter resolution across Sub-Saharan Africa. We used a large stack of GIS layers as covariates, including layers on topography, climate, geology, hydrology and land cover. As training data we used ca. 59,000 soil samples harmonized across a number of projects and datasets, and we modeled each nutrient using an ensemble of random forest and gradient boosting algorithms, implemented using the R packages ranger and xgboost. Using cross validation, we determined that significant models can be produced for organic Carbon, total (organic) Nitrogen, total Phosphorus, and extractable Phosphorous, Potassium, Calcium, Magnesium, Sulfur, Sodium, Iron, Manganese, Zinc, Copper, Aluminum and Boron, with an R-square value between 40 and 95%. The main covariates explaining spatial distribution of nutrients were precipitation and land form parameters. However, we were unable to significantly predict Sulfur, Phosphorus and Boron as these could not be correlated with any environmental covariates we used. Although the accuracy of predictions looks promising, our predictions likely suffer from the significant spatial clustering of the sampling locations, as well as a lack of more detailed data on geology and parent material at a continental scale. These results will contribute to targeting agricultural investments and interventions, as well as targeting restoration efforts and estimating yield potential and yield gaps. These results were recently published in the journal Nutrient Cycling in Agroecosystems (DOI: 10.1007/s10705-017-9870-x) and the maps are available for download under the ODC Open Database License.

  20. Impact of Submarine Groundwater Discharge on Marine Water Quality and Reef Biota of Maui

    Science.gov (United States)

    Bishop, James M.

    2016-01-01

    Generally unseen and infrequently measured, submarine groundwater discharge (SGD) can transport potentially large loads of nutrients and other land-based contaminants to coastal ecosystems. To examine this linkage we employed algal bioassays, benthic community analysis, and geochemical methods to examine water quality and community parameters of nearshore reefs adjacent to a variety of potential, land-based nutrient sources on Maui. Three common reef algae, Acanthophora spicifera, Hypnea musciformis, and Ulva spp. were collected and/or deployed at six locations with SGD. Algal tissue nitrogen (N) parameters (δ15N, N %, and C:N) were compared with nutrient and δ15N-nitrate values of coastal groundwater and nearshore surface water at all locations. Benthic community composition was estimated for ten 10-m transects per location. Reefs adjacent to sugarcane farms had the greatest abundance of macroalgae, low species diversity, and the highest concentrations of N in algal tissues, coastal groundwater, and marine surface waters compared to locations with low anthropogenic impact. Based on δ15N values of algal tissues, we estimate ca. 0.31 km2 of Kahului Bay is impacted by effluent injected underground at the Kahului Wastewater Reclamation Facility (WRF); this region is barren of corals and almost entirely dominated by colonial zoanthids. Significant correlations among parameters of algal tissue N with adjacent surface and coastal groundwater N indicate that these bioassays provided a useful measure of nutrient source and loading. A conceptual model that uses Ulva spp. tissue δ15N and N % to identify potential N source(s) and relative N loading is proposed for Hawaiʻi. These results indicate that SGD can be a significant transport pathway for land-based nutrients with important biogeochemical and ecological implications in tropical, oceanic islands. PMID:27812171

  1. Impact of Submarine Groundwater Discharge on Marine Water Quality and Reef Biota of Maui.

    Directory of Open Access Journals (Sweden)

    Daniel W Amato

    Full Text Available Generally unseen and infrequently measured, submarine groundwater discharge (SGD can transport potentially large loads of nutrients and other land-based contaminants to coastal ecosystems. To examine this linkage we employed algal bioassays, benthic community analysis, and geochemical methods to examine water quality and community parameters of nearshore reefs adjacent to a variety of potential, land-based nutrient sources on Maui. Three common reef algae, Acanthophora spicifera, Hypnea musciformis, and Ulva spp. were collected and/or deployed at six locations with SGD. Algal tissue nitrogen (N parameters (δ15N, N %, and C:N were compared with nutrient and δ15N-nitrate values of coastal groundwater and nearshore surface water at all locations. Benthic community composition was estimated for ten 10-m transects per location. Reefs adjacent to sugarcane farms had the greatest abundance of macroalgae, low species diversity, and the highest concentrations of N in algal tissues, coastal groundwater, and marine surface waters compared to locations with low anthropogenic impact. Based on δ15N values of algal tissues, we estimate ca. 0.31 km2 of Kahului Bay is impacted by effluent injected underground at the Kahului Wastewater Reclamation Facility (WRF; this region is barren of corals and almost entirely dominated by colonial zoanthids. Significant correlations among parameters of algal tissue N with adjacent surface and coastal groundwater N indicate that these bioassays provided a useful measure of nutrient source and loading. A conceptual model that uses Ulva spp. tissue δ15N and N % to identify potential N source(s and relative N loading is proposed for Hawai'i. These results indicate that SGD can be a significant transport pathway for land-based nutrients with important biogeochemical and ecological implications in tropical, oceanic islands.

  2. Impact of Submarine Groundwater Discharge on Marine Water Quality and Reef Biota of Maui.

    Science.gov (United States)

    Amato, Daniel W; Bishop, James M; Glenn, Craig R; Dulai, Henrietta; Smith, Celia M

    2016-01-01

    Generally unseen and infrequently measured, submarine groundwater discharge (SGD) can transport potentially large loads of nutrients and other land-based contaminants to coastal ecosystems. To examine this linkage we employed algal bioassays, benthic community analysis, and geochemical methods to examine water quality and community parameters of nearshore reefs adjacent to a variety of potential, land-based nutrient sources on Maui. Three common reef algae, Acanthophora spicifera, Hypnea musciformis, and Ulva spp. were collected and/or deployed at six locations with SGD. Algal tissue nitrogen (N) parameters (δ15N, N %, and C:N) were compared with nutrient and δ15N-nitrate values of coastal groundwater and nearshore surface water at all locations. Benthic community composition was estimated for ten 10-m transects per location. Reefs adjacent to sugarcane farms had the greatest abundance of macroalgae, low species diversity, and the highest concentrations of N in algal tissues, coastal groundwater, and marine surface waters compared to locations with low anthropogenic impact. Based on δ15N values of algal tissues, we estimate ca. 0.31 km2 of Kahului Bay is impacted by effluent injected underground at the Kahului Wastewater Reclamation Facility (WRF); this region is barren of corals and almost entirely dominated by colonial zoanthids. Significant correlations among parameters of algal tissue N with adjacent surface and coastal groundwater N indicate that these bioassays provided a useful measure of nutrient source and loading. A conceptual model that uses Ulva spp. tissue δ15N and N % to identify potential N source(s) and relative N loading is proposed for Hawai'i. These results indicate that SGD can be a significant transport pathway for land-based nutrients with important biogeochemical and ecological implications in tropical, oceanic islands.

  3. Radionuclide transfer to marine biota species: review of Russian language studies.

    Science.gov (United States)

    Fesenko, S; Fesenko, E; Titov, I; Karpenko, E; Sanzharova, N; Fonseca, A Gondin; Brown, J

    2010-11-01

    An extensive programme of experiments on transfer of radionuclides to aquatic species was conducted in the former USSR starting from the early 1950s. Only a few of these studies were made available in the English language literature or taken into account in international reviews of radionuclide behaviour in marine ecosystems. Therefore, an overview of original information on radionuclide transfer to marine biota species available from Russian language literature sources is presented here. The concentration ratio (CR) values for many radionuclides and for marine species such as: (239)Pu, (106)Ru and (95)Zr (crustacean), (54)Mn, (90)Sr, (95)Nb, (106)Ru, (137)Cs (239)Pu, (241)Am and natural U (molluscs), and (54)Mn, (90)Sr, (137)Cs and (144)Ce (fish) are in good agreement with those previously published, whilst for some of them, in particular, for (32)P and (110)Ag (crustaceans), (35)S (molluscs), (32)P, (35)S, (95)Nb, and (106)Ru (macroalgae) and (60)Co and (239,240)Pu (fish) the data presented here suggest that changes in the default CR reference values presented in recent marine reviews may be required. The data presented here are intended to supplement substantially the CR values being collated within the handbook on Wildlife Transfer Coefficients, coordinated under the IAEA EMRAS II programme.

  4. Radionuclide transfer to freshwater biota species: review of Russian language studies.

    Science.gov (United States)

    Fesenko, S; Fesenko, J; Sanzharova, N; Karpenko, E; Titov, I

    2011-01-01

    Around 130 publications reporting studies on radionuclide transfer to freshwater biota species conducted in the former USSR were reviewed to provide the concentration ratio values. None of these studies were available up to now in the English language reviews or publications. The values derived have been compared with the CR values used for freshwater systems in the International reviews. For some radionuclides reviewed in this paper, the data are in good agreement with the mean CR values presented earlier, however for some of them, in particular, for ²⁴¹Am (bivalve molluscs, gastropods and pelagic fish), ⁶⁰Co (gastropods, benthic fish and insect larvae), ⁹⁰Sr and ¹³⁷Cs (benthic fish and zooplankton), the mean values given here are substantially different from those presented earlier. The data reported in this paper for thirty five radionuclides and eleven groups of freshwater species markedly improve the extent of available data for evaluation of radiation impact on freshwater species. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Contrasting food web factor and body size relationships with Hg and Se concentrations in marine biota.

    Directory of Open Access Journals (Sweden)

    Roxanne Karimi

    Full Text Available Marine fish and shellfish are primary sources of human exposure to mercury, a potentially toxic metal, and selenium, an essential element that may protect against mercury bioaccumulation and toxicity. Yet we lack a thorough understanding of Hg and Se patterns in common marine taxa, particularly those that are commercially important, and how food web and body size factors differ in their influence on Hg and Se patterns. We compared Hg and Se content among marine fish and invertebrate taxa collected from Long Island, NY, and examined associations between Hg, Se, body length, trophic level (measured by δ(15N and degree of pelagic feeding (measured by δ(13C. Finfish, particularly shark, had high Hg content whereas bivalves generally had high Se content. Both taxonomic differences and variability were larger for Hg than Se, and Hg content explained most of the variation in Hg:Se molar ratios among taxa. Finally, Hg was more strongly associated with length and trophic level across taxa than Se, consistent with a greater degree of Hg bioaccumulation in the body over time, and biomagnification through the food web, respectively. Overall, our findings indicate distinct taxonomic and ecological Hg and Se patterns in commercially important marine biota, and these patterns have nutritional and toxicological implications for seafood-consuming wildlife and humans.

  6. Drivers for the establishment and composition of the sourdough lactic acid bacteria biota.

    Science.gov (United States)

    Gobbetti, Marco; Minervini, Fabio; Pontonio, Erica; Di Cagno, Raffaella; De Angelis, Maria

    2016-12-19

    The drivers for the establishment and composition of the sourdough microbiota, with particular emphasis on lactic acid bacteria, are reviewed and discussed. More than 60 different species of lactobacilli were identified from sourdoughs, showing the main overlapping between sourdough and human intestine ecosystems. The microbial kinetics during sourdough preparation was described by several studies using various methodological approaches, including culture-dependent and -independent (e.g., high throughput sequencing), and metabolite and meta-transcriptome analyses. Although the abundant microbial diversity harbored by flours, a succession of dominating and sub-dominating populations of lactic acid bacteria suddenly occurred during sourdough propagation, leading to the progressive assembly of the bacterial community. The contribution of all the potential sources (house microbiota, flour, types of flours and additional ingredients) for contaminating lactic acid bacteria was compared with the aim to find overlapping or specific routes that affect the sourdough microbiota. Once established and mature, pros and cons regarding the stability of the sourdough lactic acid bacteria biota were also reviewed, showing contradictory results, which were mainly dependent on the species/strains. Probably, the future research efforts should be dedicated to decrease the sources/drivers of noticeable variation rather than to full standardization of the process for sourdough preparation and use. Copyright © 2016. Published by Elsevier B.V.

  7. High Variability Is a Defining Component of Mediterranean-Climate Rivers and Their Biota

    Directory of Open Access Journals (Sweden)

    Núria Cid

    2017-01-01

    Full Text Available Variability in flow as a result of seasonal precipitation patterns is a defining element of streams and rivers in Mediterranean-climate regions of the world and strongly influences the biota of these unique systems. Mediterranean-climate areas include the Mediterranean Basin and parts of Australia, California, Chile, and South Africa. Mediterranean streams and rivers can experience wet winters and consequent floods to severe droughts, when intermittency in otherwise perennial systems can occur. Inter-annual variation in precipitation can include multi-year droughts or consecutive wet years. Spatial variation in patterns of precipitation (rain vs. snow combined with topographic variability lead to spatial variability in hydrologic patterns that influence populations and communities. Mediterranean streams and rivers are global biodiversity hotspots and are particularly vulnerable to human impacts. Biomonitoring, conservation efforts, and management responses to climate change require approaches that account for spatial and temporal variability (including both intra- and inter-annual. The importance of long-term data sets for understanding and managing these systems highlights the need for sustained and coordinated research efforts in Mediterranean-climate streams and rivers.

  8. Applying multibeam sonar and mathematical modeling for mapping seabed substrate and biota of offshore shallows

    Science.gov (United States)

    Herkül, Kristjan; Peterson, Anneliis; Paekivi, Sander

    2017-06-01

    Both basic science and marine spatial planning are in a need of high resolution spatially continuous data on seabed habitats and biota. As conventional point-wise sampling is unable to cover large spatial extents in high detail, it must be supplemented with remote sensing and modeling in order to fulfill the scientific and management needs. The combined use of in situ sampling, sonar scanning, and mathematical modeling is becoming the main method for mapping both abiotic and biotic seabed features. Further development and testing of the methods in varying locations and environmental settings is essential for moving towards unified and generally accepted methodology. To fill the relevant research gap in the Baltic Sea, we used multibeam sonar and mathematical modeling methods - generalized additive models (GAM) and random forest (RF) - together with underwater video to map seabed substrate and epibenthos of offshore shallows. In addition to testing the general applicability of the proposed complex of techniques, the predictive power of different sonar-based variables and modeling algorithms were tested. Mean depth, followed by mean backscatter, were the most influential variables in most of the models. Generally, mean values of sonar-based variables had higher predictive power than their standard deviations. The predictive accuracy of RF was higher than that of GAM. To conclude, we found the method to be feasible and with predictive accuracy similar to previous studies of sonar-based mapping.

  9. Doses to Terrestrial Biota in the Vicinity of BNFL Sellafield, Cumbria, UK (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Copplestone, D.; Johnson, M.S.; Jackson, D.; Jones, S.R

    2000-07-01

    Source terms and corresponding radionuclide activity concentrations in biota for {sup 134}Cs, {sup 137}Cs, {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am have been assessed for three semi-natural ecosystems in the vicinity of BNFL Sellafield, Cumbria, UK. Estimates of absorbed doses (mGy.d{sup -1}) have been calculated. Doses to key indicator species, Oniscus asellus (detritivorous invertebrate), Carabus violaceous (predatory invertebrate) and Apodemus sylvaticus (granivorous wood mouse) are discussed with reference to the 1 mGy.d{sup -1} level, below which it is postulated that no observable effects on populations in a terrestrial ecosystem occur. Implications for the 'critical group' and 'reference model' approaches for a framework of radiological environmental protection are discussed. The need to assess the most highly exposed species is advanced. New research focused on the application of biomarker techniques as a mechanism for determining the interactions and effects of environmental contaminants on ecosystem structure and functioning is presented. (author)

  10. A STUDY OF RADIOACTIVE CONTAMINATION OF MARINE BIOTA AFTER THE FUKUSHIMA ACCIDENT

    Directory of Open Access Journals (Sweden)

    V. P. Ramzaev

    2012-01-01

    Full Text Available 134Cs and 137Cs contents have been studied in 44 samples of the marine biota including four species of brown and red algae (11 samples, four species of invertebrates (8 samples and ten species of fish (25 samples. The samples have been collected in the Northwest Pacific Ocean and in the Seas of Okhotsk and Japan within the framework of the Russian monitoring program that started in 2011 to study environmental consequences of the accident at “Fukushima-1” NPP. In 2011–2012, total activity of both cesium radioisotopes for all the samples analyzed did not exceed 1 Bq kg–1 (wet weight. This value is negligible compared to the safe level of 130 Bq kg–1 (for 137Cs for the fish consumption in Russia. 134Cs, a marker of the Fukushima-derived contamination, has been determined at a level of 0.2–0.4 Bq kg–1 (wet weight for three samples of pacific saury (Cololabis saira collected from areas near Shikotan Island in Sempember 2011 and 2012. The study shows that the Fukushima accident has no considerable impact on radiation conditions in the Kuril-Kamchatka region of the Northwest Pacific Ocean and in the Russian waters of the Sea of Japan.

  11. Monitoring the Bacterial and Fungal Biota of Eleven Tobacco Grades Stored at Three Different Locations

    Directory of Open Access Journals (Sweden)

    Villemur R

    2014-12-01

    Full Text Available Tobacco as many other plants has its own microbiota. There are very few studies determining the evolution of this microbiota during tobacco storage, which may affect the quality of tobacco. Polymerase chain reaction (PCR combined with denaturing gradient gel electrophoresis (DGGE were used to determine changes in the microbiota of tobacco during the aging of eleven different tobacco grades stored at three different locations for twelve months. The microbial fraction of these tobacco grades was extracted, and the bacterial 16S and the fungal 18S ribosomal RNA gene (rDNA sequences were PCR amplified before being segregated by DGGE. The bacterial complexity of the tobacco grades was represented by DGGE migrating banding profiles that varied between 20 and 30 bands. Some variations in the banding profiles were observed between the tobacco grades, but overall no substantial changes occurred in the bacterial population of the different grades during their storage at different locations. Most of the fungal DGGE profiles were identical and had only one dominating band related to the genus Aspergillus. Bacterial and fungal isolates were also derived from the microbial fractions of the tobacco, and part of their respective 16S and 18S rDNA sequences were determined. Bacterial isolates belonged to Bacillales and gamma Protobacteria. Fungal isolates belonged to the genus Aspergillus. Our results showed that the bacterial and fungal biota of tobacco are relatively stable throughout 12 months storage time.

  12. Proposal of a weight factor for alpha radiation aiming biota radioprotection

    International Nuclear Information System (INIS)

    Pereira, Wagner de S.; Py Junior, Delcy de A.; Kelecom, Alphonse; Goncalves, Simone

    2009-01-01

    Several proposals based on the environmental radioprotection of calculating the absorbed dose in biota have been suggested. The absorbed dose expresses the deposition of energy per mass unit. The differences in biological effects of the absorbed dose can be quantified by applying a correction factor to the absorbed dose. The correction factor for radiation is easier to establish, because radiations exist in smaller number (alpha, beta, neutrons and photons) and can be set for groups of organisms. This work aims to propose a correction factor for radiation, in order to adequate the concept of absorbed dose currently used to the concept of equivalent dose. A survey of the literature on correction factors proposed for alpha radiation was carried out and, when possible, the biological endpoint was identified, as well as the radionuclide and the biological target. A variation of the weight factor for alpha radiation from 1 to 377 was observed and a number of biological endpoints, biological target and alpha emitter radionuclide were identified. Finally we propose a weight value for alpha radiation of 40, and we propose also the name of correction factor for radiation alpha as being ecological radiation weighting factor (WRE) the name 'equivalent dose for flora and fauna' (HTFF) to name of the new dose. (author)

  13. Critical appraisal of tubular putative eumetazoans from the Ediacaran Weng'an Doushantuo biota.

    Science.gov (United States)

    Cunningham, John A; Vargas, Kelly; Pengju, Liu; Belivanova, Veneta; Marone, Federica; Martínez-Pérez, Carlos; Guizar-Sicairos, Manuel; Holler, Mirko; Bengtson, Stefan; Donoghue, Philip C J

    2015-08-07

    Molecular clock analyses estimate that crown-group animals began diversifying hundreds of millions of years before the start of the Cambrian period. However, the fossil record has not yielded unequivocal evidence for animals during this interval. Some of the most promising candidates for Precambrian animals occur in the Weng'an biota of South China, including a suite of tubular fossils assigned to Sinocyclocyclicus, Ramitubus, Crassitubus and Quadratitubus, that have been interpreted as soft-bodied eumetazoans comparable to tabulate corals. Here, we present new insights into the anatomy, original composition and phylogenetic affinities of these taxa based on data from synchrotron radiation X-ray tomographic microscopy, ptychographic nanotomography, scanning electron microscopy and electron probe microanalysis. The patterns of deformation observed suggest that the cross walls of Sinocyclocyclicus and Quadratitubus were more rigid than those of Ramitubus and Crassitubus. Ramitubus and Crassitubus specimens preserve enigmatic cellular clusters at terminal positions in the tubes. Specimens of Sinocyclocyclicus and Ramitubus have biological features that might be cellular tissue or subcellular structures filling the spaces between the cross walls. These observations are incompatible with a cnidarian interpretation, in which the spaces between cross walls are abandoned parts of the former living positions of the polyp. The affinity of the Weng'an tubular fossils may lie within the algae. © 2015 The Authors.

  14. [Fungal biota in manned space environment and impact on human health].

    Science.gov (United States)

    Makimura, Koichi; Satoh, Kazuo; Sugita, Takashi; Yamazaki, Takashi

    2011-01-01

    It is important to promote microbiological research essential for long-term manned space activities under microgravity and in a completely closed environment in space craft in relation to long-duration space expeditions on the International Space Station (ISS) or to the moon and Mars in the future. Environmental monitoring data from the space shuttle, the Mir, and the ISS have already shown that microorganisms isolated from air and on inner surfaces of space craft were generally carried by crew members. The Japanese Experiment Module (JEM) "KIBO" was attached to the ISS and started its operation from 2008. It is an invaluable opportunity to begin the survey of the transition of microbiota, particularly fungal biota, in JEM from "brand-new" to "well-used" condition at various periods. Therefore, we are preparing the on-board analyzing systems for microbiota in air and on inner surfaces of ISS/JEM and normal microbiota of the astronauts themselves. In this paper, we introduce the current status and future plans on fungal research on ISS/JEM to protect flight crew members and flight hardware from potentially hazardous microorganisms from the environmental and biomedical aspects of Japan Aerospace Exploration Agency (JAXA).

  15. Offshore iron sand extraction in New Zealand: Potential trace metal exposure of benthic and pelagic biota.

    Science.gov (United States)

    Vopel, Kay; Pook, Chris; Wilson, Peter; Robertson, John

    2017-10-15

    Plans to exploit an offshore source of iron sand in South Taranaki Bight (STB), New Zealand, caused concerns that such exploitation may expose benthic and pelagic biota to elevated trace metal concentrations. We conducted dilute-acid extractions and standard elutriate tests to investigate the potential of this exploitation to (1) create a new seafloor with elevated trace metal content, (2) mobilise trace metals during iron sand extraction and, (3) enrich the returning process seawater, which feeds iron sand through mills, with trace metals. We found that recruits of freshly uncovered sediment may encounter higher-than-natural concentrations of cadmium, nickel and chromium (but not of copper, lead, and zinc) and propose to investigate the bioavailability of these metals. Elutriate test with raw and milled iron sand revealed that, for nickel and copper, dilution of the process seawater may be required to meet the local water quality guideline. We argue that this dilution can be achieved by adjustment of the mass and seawater balance of the offshore extraction process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Determining the response of African biota to climate change: using the past to model the future

    Science.gov (United States)

    Willis, K. J.; Bennett, K. D.; Burrough, S. L.; Macias-Fauria, M.; Tovar, C.

    2013-01-01

    Prediction of biotic responses to future climate change in tropical Africa tends to be based on two modelling approaches: bioclimatic species envelope models and dynamic vegetation models. Another complementary but underused approach is to examine biotic responses to similar climatic changes in the past as evidenced in fossil and historical records. This paper reviews these records and highlights the information that they provide in terms of understanding the local- and regional-scale responses of African vegetation to future climate change. A key point that emerges is that a move to warmer and wetter conditions in the past resulted in a large increase in biomass and a range distribution of woody plants up to 400–500 km north of its present location, the so-called greening of the Sahara. By contrast, a transition to warmer and drier conditions resulted in a reduction in woody vegetation in many regions and an increase in grass/savanna-dominated landscapes. The rapid rate of climate warming coming into the current interglacial resulted in a dramatic increase in community turnover, but there is little evidence for widespread extinctions. However, huge variation in biotic response in both space and time is apparent with, in some cases, totally different responses to the same climatic driver. This highlights the importance of local features such as soils, topography and also internal biotic factors in determining responses and resilience of the African biota to climate change, information that is difficult to obtain from modelling but is abundant in palaeoecological records. PMID:23878343

  17. Geological sampling data and benthic biota classification: Buzzards Bay and Vineyard Sound, Massachusetts

    Science.gov (United States)

    Ackerman, Seth D.; Pappal, Adrienne L.; Huntley, Emily C.; Blackwood, Dann S.; Schwab, William C.

    2015-01-01

    Sea-floor sample collection is an important component of a statewide cooperative mapping effort between the U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Management (CZM). Sediment grab samples, bottom photographs, and video transects were collected within Vineyard Sound and Buzzards Bay in 2010 aboard the research vesselConnecticut. This report contains sample data and related information, including analyses of surficial-sediment grab samples, locations and images of sea-floor photography, survey lines along which sea-floor video was collected, and a classification of benthic biota observed in sea-floor photographs and based on the Coastal and Marine Ecological Classification Standard (CMECS). These sample data and analyses information are used to verify interpretations of geophysical data and are an essential part of geologic maps of the sea floor. These data also provide a valuable inventory of benthic habitat and resources. Geographic information system (GIS) data, maps, and interpretations, produced through the USGS and CZM mapping cooperative, are intended to aid efforts to manage coastal and marine resources and to provide baseline information for research focused on coastal evolution and environmental change.

  18. The use of geochemical speciation modelling to predict the impact of uranium to freshwater biota

    International Nuclear Information System (INIS)

    Markich, S.J.; Brown, P.L.; Jeffree, R.A.

    1996-01-01

    Uranium is the prime potential contaminant in mine waste waters that may be released from the Ranger Uranium Mine (RUM) into the receiving waters of the Magela Creek, Alligator Rivers Region, Northern Australia. The potential ecological impact of the migration of uranium, that would result from an elevation in its concentration above background, in the Magela Creek downstream of the RUM, has been experimentally investigated by integrating biomonitoring with geochemical speciation modelling. The freshwater bivalve Velesunio angasi, abundant throughout the Magela Creek catchment, was exposed to a variety of uranium concentrations in a synthetic Magela Creek water, at four pH levels (5.0, 5.3, 5.5 and 6.0), in the presence (3.05 and 7.50 mg l -1 ) and absence of a model fulvic acid (FA), and its behavioural response was measured. Speciation modelling, using the HARPHRQ code, provided evidence that UO 2+ 2 and UO 2 OH + are the uranium species most responsible (ca. 96%) for eliciting an adverse behavioural response when UO 2+ 2 is assigned twice the toxic effect of UO 2 OH + . This finding rejects the notion that biota respond specifically to the sum total of inorganic uranyl species. (orig.)

  19. Contrasting Food Web Factor and Body Size Relationships with Hg and Se Concentrations in Marine Biota

    Science.gov (United States)

    Karimi, Roxanne; Frisk, Michael; Fisher, Nicholas S.

    2013-01-01

    Marine fish and shellfish are primary sources of human exposure to mercury, a potentially toxic metal, and selenium, an essential element that may protect against mercury bioaccumulation and toxicity. Yet we lack a thorough understanding of Hg and Se patterns in common marine taxa, particularly those that are commercially important, and how food web and body size factors differ in their influence on Hg and Se patterns. We compared Hg and Se content among marine fish and invertebrate taxa collected from Long Island, NY, and examined associations between Hg, Se, body length, trophic level (measured by δ15N) and degree of pelagic feeding (measured by δ13C). Finfish, particularly shark, had high Hg content whereas bivalves generally had high Se content. Both taxonomic differences and variability were larger for Hg than Se, and Hg content explained most of the variation in Hg:Se molar ratios among taxa. Finally, Hg was more strongly associated with length and trophic level across taxa than Se, consistent with a greater degree of Hg bioaccumulation in the body over time, and biomagnification through the food web, respectively. Overall, our findings indicate distinct taxonomic and ecological Hg and Se patterns in commercially important marine biota, and these patterns have nutritional and toxicological implications for seafood-consuming wildlife and humans. PMID:24019976

  20. Long-term affects of experimental flows on riverine biota below a reservoir

    Science.gov (United States)

    Robinson, Chris; Ortlepp, Johannes

    2010-05-01

    Large dams have altered the flow regime of most rivers on the globe with consequent effects on riverine biota. Experimental flows (multiple floods per year) have been used on the regulated Spöl River below Livigno Reservoir for over 9 years to enhance the ecological condition of the river. The flow program has improved the brown trout fishery in the river as indicated by an increased number of redds. Floods have reset periphyton assemblages from a moss-dominated streambed to one dominated by diatoms and patches of filamentous algae. Zoobenthic assemblages have shown dramatic shifts in benthic structure in line with predictions from altered state models. Ecosystem regime shifts have been characterized with increases in parameter variances followed by periods of stable states. The system appears to be entering a second zoobenthic regime shift after year 8, perhaps in response to biotic interactions due to changes in the fishery. The response patterns clearly show that a long-term perspective must be in place when assessing biotic responses to changes in physical habitat properties resulting from flow experiments.

  1. A sinemydid turtle from the Jehol Biota provides insights into the basal divergence of crown turtles.

    Science.gov (United States)

    Zhou, Chang-Fu; Rabi, Márton

    2015-11-10

    Morphological phylogenies stand in a major conflict with molecular hypotheses regarding the phylogeny of Cryptodira, the most diverse and widely distributed clade of extant turtles. However, molecular hypotheses are often considered a better estimate of phylogeny given that it is more consistent with the stratigraphic and geographic distribution of extinct taxa. That morphology fails to reproduce the molecular topology partly originates from problematic character polarization due to yet another contradiction around the composition of the cryptodiran stem lineage. Extinct sinemydids are one of these problematic clades: they have been either placed among stem-cryptodires, stem-chelonioid sea turtles, or even stem-turtles. A new sinemydid from the Early Cretaceous Jehol Biota (Yixian Formation, Barremian-Early Aptian) of China, Xiaochelys ningchengensis gen. et sp. nov., allows for a reassessment of the phylogenetic position of Sinemydidae. Our analysis indicates that sinemydids mostly share symplesiomorphies with sea turtles and their purported placement outside the crown-group of turtles is an artefact of previous datasets. The best current phylogenetic estimate is therefore that sinemydids are part of the stem lineage of Cryptodira together with an array of other Jurassic to Cretaceous taxa. Our study further emphasises the importance of using molecular scaffolds in global turtle analyses.

  2. Cernavoda NPP impact study on terrestrial and aquatic biota. Preliminary results

    International Nuclear Information System (INIS)

    Bobric, Elena; Bucur, Cristina; Popescu, Ion; Simionov, Vasile; Titescu, Gheorghe; Varlam, Carmen

    2010-01-01

    Recently, the awareness of the vulnerability of the environment has increased and the need to protect it against industrial pollutants has been recognized. The concept of sustainable development, requires new and developing international policies for environmental protection. See 'Protection of the environment from the effects of ionizing radiation' IAEA-TECDOC-1091, International Atomic Energy Agency, Vienna. As it is recommended in 'Cernavoda Unit No. 2 NPP Environmental Impact Assessment CES-03702-IAD-006', it is Cernavoda NPP responsibility to conduct an Ecological Risk Assessment study, mainly to assess the impact of nuclear power plant operation on terrestrial and aquatic biota. Long records from normal operation of Cernavoda Unit 1, wind pattern, meteorological conditions, and source terms data were used to evaluate areas of interest for environmental impact, conducting to a circle of 20 km radius around mentioned nuclear objective. The screening campaign established tritium level (because Cernavoda NPP is a CANDU type reactor, and tritium is the most important radioisotope evacuated in the environment) in air, water, soil and vegetation, focusing the interest area on particular ecosystem. Using these primary data it was evaluated which are the monitored ecological receptors and which are the measurement endpoints.This paper presents the Ecological Risk Assessment at Cernavoda NPP technical requirements, and the preliminary results of evaluating criteria for representative ecosystem components at Cernavoda NPP. (authors)

  3. Experimental taphonomy and the anatomy and diversity of the earliest fossil vertebrates (Chengjiang Biota, Cambrian, China)

    Science.gov (United States)

    Purnell, Mark; Gabbott, Sarah; Murdock, Duncan; Cong, Peiyun

    2016-04-01

    The oldest fossil vertebrates are from the Lower Cambrian Chengjiang biota of China, which contains four genera of fish-like, primitive vertebrates: Haikouichthys, Myllokunmingia, Zhongjianichthys and Zhongxiniscus. These fossils play key roles in calibrating molecular clocks and informing our view of the anatomy of animals close to the origin of vertebrates, potentially including transitional forms between vertebrates and their nearest relatives. Despite the evident importance of these fossils, the degree to which taphonomic processes have affected their anatomical completeness has not been investigated. For example, some or all might have been affected by stemward slippage - the pattern observed in experimental decay of non-biomineralised chordates in which preferential decay of synapomorphies and retention of plesiomorphic characters would cause fossil taxa to erroneously occupy more basal positions than they should. This hypothesis is based on experimental data derived from decay of non-biomineralised chordates under laboratory conditions. We have expanded this analysis to include a broader range of potentially significant environmental variables; we have also compared and combined the results of experiments from several taxa to identify general patterns of chordate decay. Examination of the Chengjiang vertebrates in the light of these results demonstrates that, contrary to some assertions, experimentally derived models of phylogenetic bias are applicable to fossils. Anatomical and phylogenetic interpretations of early vertebrates that do not take taphonomic biases into account risk overestimating diversity and the evolutionary significance of differences between fossil specimens.

  4. Effects of causeway construction on environment and biota of subtropical tidal flats in Okinawa, Japan.

    Science.gov (United States)

    Reimer, James Davis; Yang, Sung-Yin; White, Kristine N; Asami, Ryuji; Fujita, Kazuhiko; Hongo, Chuki; Ito, Shingo; Kawamura, Iori; Maeda, Isshu; Mizuyama, Masaru; Obuchi, Masami; Sakamaki, Takashi; Tachihara, Katsunori; Tamura, Maiko; Tanahara, Akira; Yamaguchi, Aika; Jenke-Kodama, Holger

    2015-05-15

    Okinawa, Japan is known for its high marine biodiversity, yet little work has been performed on examining impacts of numerous large-scale coastal development projects on its marine ecosystems. Here, we examine apparent impacts of the construction of the Kaichu-Doro causeway, which was built over 40 years ago. The causeway is a 4.75 km long embankment that divides a large tidal flat and has only two points of water exchange along its entire length. We employed quadrats, transects, sampling, visual surveys, and microbial community analyses combined with environmental, water quality data, and 1m cores, at five stations of two paired sites each (one on each side of Kaichu-Doro) to investigate how the environment and biota have changed since the Kaichu-Doro was built. Results indicate reduction in water flow, and site S1 was particularly heavily impacted by poor water quality, with low diversity and disturbed biotic communities. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Determining the response of African biota to climate change: using the past to model the future.

    Science.gov (United States)

    Willis, K J; Bennett, K D; Burrough, S L; Macias-Fauria, M; Tovar, C

    2013-01-01

    Prediction of biotic responses to future climate change in tropical Africa tends to be based on two modelling approaches: bioclimatic species envelope models and dynamic vegetation models. Another complementary but underused approach is to examine biotic responses to similar climatic changes in the past as evidenced in fossil and historical records. This paper reviews these records and highlights the information that they provide in terms of understanding the local- and regional-scale responses of African vegetation to future climate change. A key point that emerges is that a move to warmer and wetter conditions in the past resulted in a large increase in biomass and a range distribution of woody plants up to 400-500 km north of its present location, the so-called greening of the Sahara. By contrast, a transition to warmer and drier conditions resulted in a reduction in woody vegetation in many regions and an increase in grass/savanna-dominated landscapes. The rapid rate of climate warming coming into the current interglacial resulted in a dramatic increase in community turnover, but there is little evidence for widespread extinctions. However, huge variation in biotic response in both space and time is apparent with, in some cases, totally different responses to the same climatic driver. This highlights the importance of local features such as soils, topography and also internal biotic factors in determining responses and resilience of the African biota to climate change, information that is difficult to obtain from modelling but is abundant in palaeoecological records.

  6. The Stoichiometry of Nutrient Release by Terrestrial Herbivores and Its Ecosystem Consequences

    Directory of Open Access Journals (Sweden)

    Judith Sitters

    2017-04-01

    Full Text Available It is widely recognized that the release of nutrients by herbivores via their waste products strongly impacts nutrient availability for autotrophs. The ratios of nitrogen (N and phosphorus (P recycled through herbivore release (i.e., waste N:P are mainly determined by the stoichiometric composition of the herbivore's food (food N:P and its body nutrient content (body N:P. Waste N:P can in turn impact autotroph nutrient limitation and productivity. Herbivore-driven nutrient recycling based on stoichiometric principles is dominated by theoretical and experimental research in freshwater systems, in particular interactions between algae and invertebrate herbivores. In terrestrial ecosystems, the impact of herbivores on nutrient cycling and availability is often limited to studying carbon (C:N and C:P ratios, while the role of terrestrial herbivores in mediating N:P ratios is also likely to influence herbivore-driven nutrient recycling. In this review, we use rules and predictions on the stoichiometry of nutrient release originating from algal-based aquatic systems to identify the factors that determine the stoichiometry of nutrient release by herbivores. We then explore how these rules can be used to understand the stoichiometry of nutrient release by terrestrial herbivores, ranging from invertebrates to mammals, and its impact on plant nutrient limitation and productivity. Future studies should focus on measuring both N and P when investigating herbivore-driven nutrient recycling in terrestrial ecosystems, while also taking the form of waste product (urine or feces and other pathways by which herbivores change nutrients into account, to be able to quantify the impact of waste stoichiometry on plant communities.

  7. The stoichiometry of nutrient release by terrestrial herbivores and its ecosystem consequences

    Science.gov (United States)

    Sitters, Judith; Bakker, Elisabeth S.; Veldhuis, Michiel P.; Veen, G. F.; Olde Venterink, Harry; Vanni, Michael J.

    2017-04-01

    It is widely recognized that the release of nutrients by herbivores via their waste products strongly impacts nutrient availability for autotrophs. The ratios of nitrogen (N) and phosphorus (P) recycled through herbivore release (i.e., waste N:P) are mainly determined by the stoichiometric composition of the herbivore’s food (food N:P) and its body nutrient content (body N:P). Waste N:P can in turn impact autotroph nutrient limitation and productivity. Herbivore-driven nutrient recycling based on stoichiometric principles is dominated by theoretical and experimental research in freshwater systems, in particular interactions between algae and invertebrate herbivores. In terrestrial ecosystems, the impact of herbivores on nutrient cycling and availability is often limited to studying carbon (C ):N and C:P ratios, while the role of terrestrial herbivores in mediating N:P ratios is also likely to influence herbivore-driven nutrient recycling. In this review, we use rules and predictions on the stoichiometry of nutrient release originating from algal-based aquatic systems to identify the factors that determine the stoichiometry of nutrient release by herbivores. We then explore how these rules can be used to understand the stoichiometry of nutrient release by terrestrial herbivores, ranging from invertebrates to mammals, and its impact on plant nutrient limitation and productivity. Future studies should focus on measuring both N and P when investigating herbivore-driven nutrient recycling in terrestrial ecosystems, while also taking the form of waste product (urine or feces) and other pathways by which herbivores change nutrients into account, to be able to quantify the impact of waste stoichiometry on plant communities.

  8. Watch: Current knowledge of the terrestrial Global Water Cycle"

    NARCIS (Netherlands)

    Harding, R.; Best, M.; Hagemann, S.; Kabat, P.; Tallaksen, L.M.; Warnaars, T.; Wiberg, D.; Weedon, G.P.; Lanen, van H.A.J.; Ludwig, F.; Haddeland, I.

    2011-01-01

    Water-related impacts are among the most important consequences of increasing greenhouse gas concentrations. Changes in the global water cycle will also impact the carbon and nutrient cycles and vegetation patterns. There is already some evidence of increasing severity of floods and droughts and

  9. Comparing the Life Cycle Energy Consumption, Global ...

    Science.gov (United States)

    Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG) emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energyand carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage) centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability

  10. Fuel cycle

    International Nuclear Information System (INIS)

    Bahm, W.

    1989-01-01

    The situation of the nuclear fuel cycle for LWR type reactors in France and in the Federal Republic of Germany was presented in 14 lectures with the aim to compare the state-of-the-art in both countries. In addition to the momentarily changing fuilds of fuel element development and fueling strategies, the situation of reprocessing, made interesting by some recent developmnts, was portrayed and differences in ultimate waste disposal elucidated. (orig.) [de

  11. Halogenated organic pollutants in marine biota from the Xuande Atoll, South China Sea: Levels, biomagnification and dietary exposure.

    Science.gov (United States)

    Sun, Yu-Xin; Hu, Yong-Xia; Zhang, Zai-Wang; Xu, Xiang-Rong; Li, Heng-Xiang; Zuo, Lin-Zi; Zhong, Yi; Sun, Hong; Mai, Bi-Xian

    2017-05-15

    Six marine biota species were collected from the Xuande Atoll, South China Sea to investigate the bioaccumulation of dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE) and dechlorane plus (DP). Pike conger (Muraenesox talabonoides) had the highest concentrations of halogenated organic pollutants (HOPs) among the six marine biota species. DDTs were the predominant HOPs, followed by PCBs and PBDEs, with minor contributions of DBDPE and DP. Twenty-one percent of samples had ratios of (DDE+DDD)/ΣDDTs lower than 0.5, implying the presence of fresh DDT inputs in the environment of the Xuande Atoll. The biomagnification factor values for DDTs, PCBs, PBDEs and DP were higher than 1, suggesting biomagnification of these contaminants in the marine food chains. Consumption of seafood from the Xuande Atoll might not subject local residents in the coastal areas of South China to health risks as far as HOPs are concerned. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Persistent organic pollutants and mercury in marine biota of the Canadian Arctic: an overview of spatial and temporal trends.

    Science.gov (United States)

    Braune, B M; Outridge, P M; Fisk, A T; Muir, D C G; Helm, P A; Hobbs, K; Hoekstra, P F; Kuzyk, Z A; Kwan, M; Letcher, R J; Lockhart, W L; Norstrom, R J; Stern, G A; Stirling, I

    2005-12-01

    This review summarizes and synthesizes the significant amount of data which was generated on mercury (Hg) and persistent organic pollutants (POPs) in Canadian Arctic marine biota since the first Canadian Arctic Contaminants Assessment Report (CACAR) was published in 1997. This recent body of work has led to a better understanding of the current levels and spatial and temporal trends of contaminants in biota, including the marine food species that northern peoples traditionally consume. Compared to other circumpolar countries, concentrations of many organochlorines (OCs) in Canadian Arctic marine biota are generally lower than in the European Arctic and eastern Greenland but are higher than in Alaska, whereas Hg concentrations are substantially higher in Canada than elsewhere. Spatial coverage of OCs in ringed seals, beluga and seabirds remains a strength of the Arctic contaminant data set for Canada. Concentrations of OCs in marine mammals and seabirds remain fairly consistent across the Canadian Arctic although subtle differences from west to east and south to north are found in the proportions of various chemicals. The most significant development since 1997 is improvement in the temporal trend data sets, thanks to the use of archived tissue samples from the 1970s and 1980s, long-term studies using archeological material, as well as the continuation of sampling. These data cover a range of species and chemicals and also include retrospective studies on new chemicals such as polybrominated diphenyl ethers. There is solid evidence in a few species (beluga, polar bear, blue mussels) that Hg at some locations has significantly increased from pre-industrial times to the present; however, the temporal trends of Hg over the past 20-30 years are inconsistent. Some animal populations exhibited significant increases in Hg whereas others did not. Therefore, it is currently not possible to determine if anthropogenic Hg is generally increasing in Canadian Arctic biota. It is

  13. The role of regional information in the dose rate estimation of biota: from the view point of stakeholder involvement

    International Nuclear Information System (INIS)

    Urabe, Itsumasa

    2008-01-01

    A dose evaluation system developed to judge environmental radiation safety was proposed in order to evaluate the effect on environmental flora and fauna. However, it was noted that large differences exist between biota doses based on the regional data and those determined by the dose evaluation system developed. In order to realize successful mutual communication among stakeholders, information needed for environmental radiation protection has been investigated in various kinds of exposure situations, because the Japanese tend to act following the standards set by them to get the most appropriate results in the situations they are faced with. It became clear from the investigation on beliefs about environmental issues that the Japanese are concerned about regional characteristics of natural environments and biota through which they observe variations in their living conditions. Furthermore, the systematic approach for compilation of the regional environmental parameters and data becomes important to accomplish a social agreement on environmental safety. (author)

  14. Long-term and realistic global change manipulations had low impact on diversity of soil biota in temperate heathland

    DEFF Research Database (Denmark)

    Holmstrup, Martin; Damgaard, Christian; Schmidt, Inger K

    2017-01-01

    C:N ratio. After eight years of treatment, however, the CO2-increased litter C:N ratio did not influence the diversity in any of the four fauna groups. The number of significant correlations between treatments, food source quality, and soil biota diversities was reduced from six to three after two...... and eight years, respectively. These results suggest a remarkable resilience within the soil biota against global climate change treatments in the long term.......In a dry heathland ecosystem we manipulated temperature (warming), precipitation (drought) and atmospheric concentration of CO2 in a full-factorial experiment in order to investigate changes in below-ground biodiversity as a result of future climate change. We investigated the responses...

  15. Dynamics of radiation exposure to marine biota in the area of the Fukushima NPP in March–May 2011

    International Nuclear Information System (INIS)

    Kryshev, I.I.; Kryshev, A.I.; Sazykina, T.G.

    2012-01-01

    Estimates of radiation dose rates are presented for marine biota in March–May 2011 in the coastal zone near Fukushima NPP, and in the open sea. Calculations of fish contamination were made using two methods: a concentration factor approach, and a dynamic model. For representative marine organisms (fish and molluscs) the radiation dose rates did not exceed the reference level of 10 mGy/day. At a distance 30 km from the NPP, in the open sea the radiation doses for marine biota were much lower than those in the coastal zone near the NPP. Comparative estimates are presented for radiation doses to aquatic organisms in the exclusion zones of the Eastern Urals Radioactive Trail, and the Chernobyl NPP.

  16. Nutrient acquisition strategies of mammalian cells.

    Science.gov (United States)

    Palm, Wilhelm; Thompson, Craig B

    2017-06-07

    Mammalian cells are surrounded by diverse nutrients, such as glucose, amino acids, various macromolecules and micronutrients, which they can import through transmembrane transporters and endolysosomal pathways. By using different nutrient sources, cells gain metabolic flexibility to survive periods of starvation. Quiescent cells take up sufficient nutrients to sustain homeostasis. However, proliferating cells depend on growth-factor-induced increases in nutrient uptake to support biomass formation. Here, we review cellular nutrient acquisition strategies and their regulation by growth factors and cell-intrinsic nutrient sensors. We also discuss how oncogenes and tumour suppressors promote nutrient uptake and thereby support the survival and growth of cancer cells.

  17. Application of bio-indication approach for an assessment of natural radionuclides impact on biota in post-mining areas

    International Nuclear Information System (INIS)

    Geraskin, Stanislav; Dikareva, Nina; Dikarev, Vladimir; Oudalova, Alla; Michalik, Boguslaw; Wysocka, Malgorzata; Chalupnik, Stanislaw

    2006-01-01

    , 1978) for environmental monitoring. There are many reasons for using plant systems. Plant bioassays provide meaningful parameters to assess the toxicity of complex mixtures like industrial wastes (Rank, Nielsen, 1998) even without knowledge of its chemical composition. In contrast to the specific nature of assessments on exposure, studies of biological effects integrate the impacts of all the harmful agents, including synergistic and antagonistic effects. This approach is particularly useful for assessing unknown contaminants, complex mixtures, or hazardous wastes. Thus, a correct estimation of the environment pollution risk needs to be derived from biological tests and pollutant chemical control in ecosystem compartments. Both need to be carried out simultaneously. Hence, the simultaneous use of chemical and biological control methods allows an identification of the relationships between the pollutant concentrations and the biological effects that they cause. In turn, such relationships may allow identifying the contribution of each specific pollutant to the overall biological effect observed. The knowledge generated makes it possible to limit the action of unfavorable factors on biota and to predict the further ecological alterations in regions submitted to intensive industrial impact. Interaction of contaminants with biota takes place firstly at the cellular level. It is not only the first manifestation of harmful effects, but also suitable tools for an early and sensitive detection of the risk. Therefore, just genetic test-systems should be used for an early and reliable monitoring of the alterations resulting from the human activity. The present work is focused on: 1) evaluating and comparing the genotoxic potential of two types of samples (water and sediment) by employing root meristem cells of Allium cepa; 2) finding out biological markers that are simple to be scanned and linked to contents of key pollutants in water and sediment samples from post-mining areas

  18. Application of bio-indication approach for an assessment of natural radionuclides impact on biota in post-mining areas

    Energy Technology Data Exchange (ETDEWEB)

    Geraskin, Stanislav; Dikareva, Nina; Dikarev, Vladimir; Oudalova, Alla [Russian Institute of Agricultural Radiology and Agroecology. RIARAE, Obninsk (Russian Federation); Michalik, Boguslaw; Wysocka, Malgorzata; Chalupnik, Stanislaw [Central Mining Institute, Katowice (Poland)

    2006-07-01

    , 1978) for environmental monitoring. There are many reasons for using plant systems. Plant bioassays provide meaningful parameters to assess the toxicity of complex mixtures like industrial wastes (Rank, Nielsen, 1998) even without knowledge of its chemical composition. In contrast to the specific nature of assessments on exposure, studies of biological effects integrate the impacts of all the harmful agents, including synergistic and antagonistic effects. This approach is particularly useful for assessing unknown contaminants, complex mixtures, or hazardous wastes. Thus, a correct estimation of the environment pollution risk needs to be derived from biological tests and pollutant chemical control in ecosystem compartments. Both need to be carried out simultaneously. Hence, the simultaneous use of chemical and biological control methods allows an identification of the relationships between the pollutant concentrations and the biological effects that they cause. In turn, such relationships may allow identifying the contribution of each specific pollutant to the overall biological effect observed. The knowledge generated makes it possible to limit the action of unfavorable factors on biota and to predict the further ecological alterations in regions submitted to intensive industrial impact. Interaction of contaminants with biota takes place firstly at the cellular level. It is not only the first manifestation of harmful effects, but also suitable tools for an early and sensitive detection of the risk. Therefore, just genetic test-systems should be used for an early and reliable monitoring of the alterations resulting from the human activity. The present work is focused on: 1) evaluating and comparing the genotoxic potential of two types of samples (water and sediment) by employing root meristem cells of Allium cepa; 2) finding out biological markers that are simple to be scanned and linked to contents of key pollutants in water and sediment samples from post-mining areas

  19. Assessment of doses to non-human biota: Review of developments and demonstration assessment for Olkiluoto repository

    International Nuclear Information System (INIS)

    Smith, K.; Robinson, C.

    2006-12-01

    This report provides a summary of work commissioned by Posiva Oy and undertaken by Enviros Consulting Ltd to support the development of a strategy for the assessment of environmental impacts from ionising radiation associated with the Olkiluoto waste repository, Finland, as part of the development of the Posiva Safety Case Portfolio. This project included a review of the development of international policies and standards related to protection of biota from the effects of ionizing radiation and of biota assessment methodologies, paying particular attention to those that have been applied to waste repository performance assessments. On the basis of this review, recommendations were developed on the most appropriate methodology to apply in order to assess the impact of radioactive releases from the planned spent fuel repository in Olkiluoto. A test-case was developed, in collaboration with staff from Posiva and Facilia AB, and an assessment was performed. The results and experience of which were analysed and summarised to develop recommendations for a future strategy. The test case highlighted some significant data gaps related to the assessment of impacts to both generic biota types and to interest species. In particular, concentration ratios for generic carnivorous mammals and migratory species such as moose that may consume food from multiple ecosystems and dose conversion factors for large burrowing (i.e. hibernating) mammals. However, in general terms, the dose rates predicted for all organism types were several orders of magnitude below those at which population effects would be expected to be observed and those at which effects on the individual may be anticipated. There would therefore be scope for simplifying the approach applied, although there would be value in performing a sensitivity analysis to ensure that the simplification is applied appropriately. There would also be value in ensuring consistency of the developing approach for non-human biota with

  20. TOR Signaling and Nutrient Sensing.

    Science.gov (United States)

    Dobrenel, Thomas; Caldana, Camila; Hanson, Johannes; Robaglia, Christophe; Vincentz, Michel; Veit, Bruce; Meyer, Christian

    2016-04-29

    All living organisms rely on nutrients to sustain cell metabolism and energy production, which in turn need to be adjusted based on available resources. The evolutionarily conserved target of rapamycin (TOR) protein kinase is a central regulatory hub that connects environmental information about the quantity and quality of nutrients to developmental and metabolic processes in order to maintain cellular homeostasis. TOR is activated by both nitrogen and carbon metabolites and promotes energy-consuming processes such as cell division, mRNA translation, and anabolism in times of abundance while repressing nutrient remobilization through autophagy. In animals and yeasts, TOR acts antagonistically to the starvation-induced AMP-activated kinase (AMPK)/sucrose nonfermenting 1 (Snf1) kinase, called Snf1-related kinase 1 (SnRK1) in plants. This review summarizes the immense knowledge on the relationship between TOR signaling and nutrients in nonphotosynthetic organisms and presents recent findings in plants that illuminate the crucial role of this pathway in conveying nutrient-derived signals and regulating many aspects of metabolism and growth.

  1. Nutrient canal of the fibula

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo-Hyuk; Ehara, Shigeru; Tamakawa, Yoshiharu [Departments of Radiology, Iwate Medical University School of Medicine, Morioka (Japan); Horiguchi, Masahura [Department of Anatomy I, Iwate Medical University School of Medicine, Morioka (Japan)

    2000-01-01

    Objective. To investigate the radiological features of the nutrient canal in the fibula.Design and patients. One hundred and seventy-nine dried fibulae were studied regarding the type, number, location, and direction of the nutrient canal. They were classified into a usual type (type I: a radiolucent line confined to the cortex) and an atypical type (type II: a radiolucent line extending beyond the cortex).Results. Among the total of 230 nutrient canals seen on radiography, 197 (86%) were type I and 33 (14%) were type II. On CT scans, the ossified rim of the canal extended into the medullary cavity in type II canals. The most common site was the posteromedial aspect in both type I and type II canals. Type II canals were significantly more common in fibulae with two or three nutrient canals. The frequency of the upward direction was more common in type II canals.Conclusion. Nutrient canals with extension of the ossified rim into the medullary canal are the cause of linear lucency that may simulate a fracture. Their features are slightly different from those of usual canals. (orig.)

  2. Nutrient limitation in tropical secondary forests following different management practices.

    Science.gov (United States)

    Nagy, R Chelsea; Rastetter, Edward B; Neill, Christopher; Porder, Stephen

    2017-04-01

    Secondary forests now make up more than one-half of all tropical forests, and constraints on their biomass accumulation will influence the strength of the terrestrial carbon (C) sink in the coming decades. However the variance in secondary tropical forest biomass for a given stand age and climate is high and our understanding of why is limited. We constructed a model of terrestrial C, nitrogen (N), and phosphorus (P) cycling to examine the influence of disturbance and management practices on nutrient limitation and biomass recovery in secondary tropical forests. The model predicted that N limited the rate of forest recovery in the first few decades following harvest, but that this limitation switched to P approximately 30-40 yr after abandonment, consistent with field data on N and P cycling from secondary tropical forest chronosequences. Simulated biomass recovery agreed well with field data of biomass accumulation following harvest (R 2  = 0.80). Model results showed that if all biomass remained on site following a severe disturbance such as blowdown, regrowth approached pre-disturbance biomass in 80-90 yr, and recovery was faster following smaller disturbances such as selective logging. Field data from regrowth on abandoned pastures were consistent with simulated losses of nutrients in soil organic matter, particularly P. Following any forest disturbance that involved the removal of nutrients (i.e., except blowdown), forest regrowth produced reduced biomass relative to the initial state as a result of nutrient loss through harvest, leaching and/or sequestration by secondary minerals. Differences in nutrient availability accounted for 49-94% of the variance in secondary forest biomass C at a given stand age. Management lessons from this study are the importance of strategies that help retain nutrients on site, recognizing the role of coarse woody debris in immobilization and subsequent release of nutrients, and the potential for nutrient additions to enhance

  3. Comparative radiation impact on biota and man in the area affected by the accident at the Chernobyl nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Fesenko, S.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation) and International Atomic Energy Agency, Agency' s Laboratories, Seibersdorf A-2444 (Austria)]. E-mail: s.fesenko@iaea.org; Alexakhin, R.M. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Geras' kin, S.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Sanzharova, N.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spirin, Ye.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spiridonov, S.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Gontarenko, I.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Strand, P. [Norwegian Radiation Protection Authority, Oesteras (Norway)

    2005-07-01

    A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30 km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated. It has been found that in 1986 (early period after the accident) the emergency radiation standards for man do not guarantee adequate protection of the environment, some species of which could be affected more than man. In 1991 RIFs for man were considerably (by factor of 20.0-1.1 x 10{sup 5}) higher compared with those for selected non-human species. Thus, for the long term after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well.

  4. Nutrient-driven poleward expansion of the Northeast Atlantic mackerel (Scomber scombrus stock: A new hypothesis

    Directory of Open Access Journals (Sweden)

    Selma V. Pacariz

    2016-05-01

    Full Text Available Abstract The Northeast Atlantic mackerel (Scomber scombrus stock has increased and expanded its summer feeding migration west- and northwards since 2006, entailing large geopolitical challenges for the countries harvesting this species. A common perspective is that climatic warming opens up new regions for biota in the north. It has also been suggested that the presently large pelagic fish stocks deplete prey resources in the eastern North Atlantic during their summer feeding phase, forcing the stocks west towards the Irminger Sea in their search for food. Here, we suggest that the declining nutrient (silicate concentrations observed along the northern European continental slope reduce primary and thus secondary production, exacerbating food scarceness in the east and adding to the incentive to migrate westward. The new westward feeding route requires that the fish cross the Iceland Basin, which during the summer season quickly becomes nutrient-depleted and thus might act as a barrier to migration after the spring bloom. Using mackerel and zooplankton abundance data from the International Ecosystem Summer Surveys in the Nordic Seas, we suggest that the oligotrophic waters in the central Iceland Basin force the fish to migrate through a narrow ‘corridor’ along the south Iceland shelf, where nutrients are replenished and both primary and secondary production are higher.

  5. Nutrient supply of plants in aquaponic systems

    OpenAIRE

    Andras Bittsanszky; Nikolett Uzinger; Gábor Gyulai; Alex Mathis; Ranka Junge; Morris Villarroel; Benzion Kotzen; Tamas Komives

    2016-01-01

    In this preliminary article we present data on plant nutrient concentrations in aquaponic systems, and compare them to nutrient concentrations in “standard” hydroponic solutions. Our data shows that the nutrient concentrations supplied by the fish in aquaponic system are significantly lower for most nutrients, compared to hydroponic systems. Nevertheless, plants do thrive in solutions that have lower nutrient levels than “standard” hydroponic solutions. This is especially true for green leafy...

  6. Plants cause ecosystem nutrient depletion via the interruption of bird-derived spatial subsidies

    Science.gov (United States)

    Young, Hillary S.; McCauley, Douglas J.; Dunbar, Robert B.; Dirzo, Rodolfo

    2010-01-01

    Plant introductions and subsequent community shifts are known to affect nutrient cycling, but most such studies have focused on nutrient enrichment effects. The nature of plant-driven nutrient depletions and the mechanisms by which these might occur are relatively poorly understood. In this study we demonstrate that the proliferation of the commonly introduced coconut palm, Cocos nucifera, interrupts the flow of allochthonous marine subsidies to terrestrial ecosystems via an indirect effect: impact on birds. Birds avoid nesting or roosting in C. nucifera, thus reducing the critical nutrient inputs they bring from the marine environment. These decreases in marine subsidies then lead to reductions in available soil nutrients, decreases in leaf nutrient quality, diminished leaf palatability, and reduced herbivory. This nutrient depletion pathway contrasts the more typical patterns of nutrient enrichment that follow plant species introductions. Research on the effects of spatial subsidy disruptions on ecosystems has not yet examined interruptions driven by changes within the recipient community, such as plant community shifts. The ubiquity of coconut palm introductions across the tropics and subtropics makes these observations particularly noteworthy. Equally important, the case of C. nucifera provides a strong demonstration of how plant community changes can dramatically impact the supply of allochthonous nutrients and thereby reshape energy flow in ecosystems. PMID:20133852

  7. Nutrient Limitation of Microbial Mediated Decomposition and Arctic Soil Chronology

    Science.gov (United States)

    Melle, C. J.; Darrouzet-Nardi, A.; Wallenstein, M. D.

    2012-12-01

    Soils of northern permafrost regions currently contain twice as much carbon as the entire Earth's atmosphere. Traditionally, environmental constraints have limited microbial activity resulting in restricted decomposition of soil organic matter in these systems and accumulation of massive amounts of soil organic carbon (SOC), however climate change is reducing the constraints of decomposition in arctic permafrost regions. Carbon cycling in nutrient poor, arctic ecosystems is tightly coupled to other biogeochemical cycles. Several studies have suggested strong nitrogen limitations of primary productivity and potentially warm-season microbial activity in these nutrient deficient soils. Nitrogen is required for microbial extracellular enzyme production which drives the decomposition of soil organic matter (SOM). Nitrogen limited arctic soils may also experience limitation via labile carbon availability despite the SOM rich environment due to low extracellular enzyme production. Few studies have directly addressed nutrient induced microbial limitation in SOC rich arctic tundra soils, and even less is known about the potential for nutrient co-limitation. Additionally, through the process of becoming deglaciated, sites within close proximity to one another may have experienced drastic differences in their effective soil ages due to the varied length of their active histories. Many soil properties and nutrient deficiencies are directly related to soil age, however this chronology has not previously been a focus of research on nutrient limitation of arctic soil microbial activity. Understanding of nutrient limitations, as well as potential co-limitation, on arctic soil microbial activity has important implications for carbon cycling and the ultimate fate of the current arctic SOC reservoir. Analyses of nutrient limitation on soils of a single site are not adequate for fully understanding the controls on soil microbial activity across a vast land mass with large variation in

  8. Soil nutrient availability and reproductive effort drive patterns in nutrient resorption in Pentachlethra macroloba

    Science.gov (United States)

    K. L. Tully; Tana Wood; A. M. Schwantes; D. Lawrence

    2013-01-01

    The removal of nutrients from senescing tissues, nutrient resorption, is a key strategy for conserving nutrients in plants. However, our understanding of what drives patterns of nutrient resorption in tropical trees is limited. We examined the effects of nutrient sources (stand-level and tree-level soil fertility) and sinks (reproductive effort) on nitrogen (N) and...

  9. Microbial extracellular enzymes in biogeochemical cycling of ecosystems.

    Science.gov (United States)

    Luo, Ling; Meng, Han; Gu, Ji-Dong

    2017-07-15

    Extracellular enzymes, primarily produced by microorganisms, affect ecosystem processes because of their essential roles in degradation, transformation and mineralization of organic matter. Extracellular enzymes involved in the cycling of carbon (C), nitrogen (N) and phosphorus (P) have been widely investigated in many different ecosystems, and several enzymes have been recognized as key components in regulating C storage and nutrient cycling. In this review, it was the first time to summarize the specific extracellular enzymes related to C storage and nutrient cycling for better understanding the important role of microbial extracellular enzymes in biogeochemical cycling of ecosystems. Subsequently, ecoenzymatic stoichiometry - the relative ratio of extracellular enzyme, has been reviewed and further provided a new perspective for understanding biogeochemical cycling of ecosystems. Finally, the new insights of using microbial extracellular enzyme in indicating biogeochemical cycling and then protecting ecosystems have been suggested. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Happy Cycling

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte; Nielsen, Tom

    2013-01-01

    Artiklens formål er at diskutere oplevede kvaliteter og adfærdsaspekter af mobilitet med udgangspunkt i spørgsmålet om cykling i byer og relationen mellem design og adfærd. Artiklen tager afsæt i et studie forløb der involverede studerende fra Urban Design, Industriel Design Arkitektskolen Aarhus...... og Interaktions Design, Aarhus Universitet under opgave teamet: ”Happy Cycling City – Aarhus”. Udfordringen i studieopgaven var at vise nye attraktive løsningsmuligheder i forhold til cyklens og cyklismens integration i byrum samt at påpege relationen mellem design og overordnede diskussioner af...

  11. Nutrient-enhancement of Matooke banana for improved nutrient ...

    African Journals Online (AJOL)

    A total of 173 PLHIVregistered with Rakai Health Science Project were chosen and interviewed using structured questionnaires to determine the current contribution of banana to the household food security. Nutrient intake data were collected using Gibson s 24-