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Soil chemistry

Tomás Bosco, Mónica Beatriz Bertiller, Analía Lorena Carrera
Assessing the ability of key species to cope with environmental stresses in disturbed areas is an important issue for recovery of degraded arid ecosystem. Our objective was to evaluate the effect of soil moisture, exposure to UV radiation, and presence/absence of litter with different chemistry on soil N, recruitment and biomass of seedlings of perennial grass (Poa ligularis and Nassella tenuis) and evergreen shrub species (Atriplex lampa and Larrea divaricata) in denuded areas. We carried out a microcosm experiment with soil blocks (28 cm depth) sowed with seeds of the target species, subjected to different levels of litter type (perennial grass-evergreen shrub mixture, evergreen shrub mixture, and no litter), UV radiation (near ambient and reduced UV), and soil water (high: 15-25% and low 5-15%)...
April 16, 2018: Journal of Environmental Management
Thomas R Stoughton, Ricardo Kriebel, Diana D Jolles, Robin L O'Quinn
PREMISE OF THE STUDY: Species formation is an intuitive endpoint of reproductive isolation, but circumscribing taxa that arise during speciation can be difficult because of gene flow, morphological continuity, hybridization or polyploidization, and low sequence variation among newly diverged lineages. Nonetheless, species complexes are ubiquitous, and their classification is essential for understanding how diversity influences ecosystem function. METHODS: We used modern sequencing technology to identify lineages of perennial Claytonia L...
April 19, 2018: American Journal of Botany
Seung-Mann Paek
The recent development of analogs of brefeldin A (BFA), a fungal metabolite, for the improvement of BFA apoptosis-inducing activity is described. BFA has been isolated from various soil or, more recently, marine fungi and has shown versatile beneficial activities. More importantly, the apoptosis-inducing activity of BFA in cancer cells highlights the possibility of further developing this natural product as an anticancer agent. Besides its biological importance, its structural features have also gathered tremendous interest from both medicinal and synthetic chemists...
April 18, 2018: Marine Drugs
Daniel G Strawn
Arsenic is a non-essential element that poses risks in many environments, including soil, groundwater, and surface water. Insights into the environmental biogeochemistry of As can be gained by comparing As and P reaction processes. Arsenic and P are chemical analogues, and it is proposed that they have similar chemical behaviors in environmental systems. However some chemical properties of As and P are distinct, such as redox reactions, causing the biogeochemical behavior of the two elements to differ. In the environment, As occurs as either As(V) or As(III) oxyanions (e...
April 2, 2018: Geochemical Transactions
Xu Zhang, Xinxin Li, Huanhuan Yang, Zhaojie Cui
This study focused on the bioremediation mechanisms of lead (0, 100, 500, 1000 mg kg-1 ) and cadmium (0,10,50,100 mg kg-1 ) contaminated soil using two indigenous fungi selected from mine tailings as the phytostimulation of Arabidopsis thaliana. The two fungal strains were characterized as Mucor circinelloides (MC) and Trichoderma asperellum (TA) by internal transcribed spacer sequencing at the genetic levels. Our research revealed that Cadmium was more toxic to plant growth than lead and meanwhile, MC and TA can strengthen A...
March 29, 2018: Ecotoxicology and Environmental Safety
James Johnson, Elisabeth Graf Pannatier, Stefano Carnicelli, Guia Cecchini, Nicholas Clarke, Nathalie Cools, Karin Hansen, Henning Meesenburg, Tiina M Nieminen, Gunilla Pihl Karlsson, Hugues Titeux, Elena Vanguelova, Arne Verstraeten, Lars Vesterdal, Peter Waldner, Mathieu Jonard
Acid deposition arising from sulphur (S) and nitrogen (N) emissions from fossil fuel combustion and agriculture has contributed to the acidification of terrestrial ecosystems in many regions globally. However, in Europe and North America, S deposition has greatly decreased in recent decades due to emissions controls. In this study we assessed the response of soil solution chemistry in mineral horizons of European forests to these changes. Trends in pH, acid neutralising capacity (ANC), major ions, total aluminium (Altot ), and dissolved organic carbon (DOC) were determined for the period 1995-2012...
March 31, 2018: Global Change Biology
T Michael Anderson, Daniel M Griffith, James B Grace, Eric M Lind, Peter B Adler, Lori A Biederman, Dana M Blumenthal, Pedro Daleo, Jennifer Firn, Nicole Hagenah, W Stanley Harpole, Andrew S MacDougall, Rebecca L McCulley, Suzanne M Prober, Anita C Risch, Mahesh Sankaran, Martin Schütz, Eric W Seabloom, Carly J Stevens, Lauren L Sullivan, Peter D Wragg, Elizabeth T Borer
Plant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects. We addressed this goal by measuring plant elemental (C, N, P and K) responses to eutrophication and vertebrate herbivore exclusion at eighteen sites on six continents. Across sites, climate and atmospheric N deposition emerged as strong predictors of plot-level tissue nutrients, mediated by biomass and plant chemistry...
April 2018: Ecology
Xingyue Yang, Xin Tian, Yannan Zhou, Yali Liu, Xinlong Li, Tingting Lu, Changhe Yu, Liyun He
Background: Daodi medicinal material is widely used in Chinese herb medication. However, there is a lack of systematic methodology for identifying characteristics associated with good quality and reliable efficacy of Daodi med-material. Purpose: The purpose of this study is to provide some evidence to further substantiate the use of Daodi medicinal materials. Methods: Seven relevant databases were searched before July 2014. Two evaluators were responsible for screening and categorizing the results...
2018: Evidence-based Complementary and Alternative Medicine: ECAM
Susan R Kennedy, Todd E Dawson, Rosemary G Gillespie
The Hawaiian Islands offer a unique opportunity to test how changes in the properties of an isolated ecosystem are propagated through the organisms that occur within that ecosystem. The age-structured arrangement of volcanic-derived substrates follows a regular progression over space and, by inference, time. We test how well documented successional changes in soil chemistry and associated vegetation are reflected in organisms at higher trophic levels-specifically, predatory arthropods (spiders)-across a range of functional groups...
2018: PeerJ
Ildikó Szelecz, Isabelle Koenig, Christophe V W Seppey, Renée-Claire Le Bayon, Edward A D Mitchell
Decomposing vertebrate cadavers release large, localized inputs of nutrients. These temporally limited resource patches affect nutrient cycling and soil organisms. The impact of decomposing cadavers on soil chemistry is relevant to soil biology, as a natural disturbance, and forensic science, to estimate the postmortem interval. However, cadaver impacts on soils are rarely studied, making it difficult to identify common patterns. We investigated the effects of decomposing pig cadavers (Sus scrofa domesticus) on soil chemistry (pH, ammonium, nitrate, nitrogen, phosphorous, potassium and carbon) over a one-year period in a spruce-dominant forest...
March 6, 2018: Forensic Science International
Kateryna Zhalnina, Katherine B Louie, Zhao Hao, Nasim Mansoori, Ulisses Nunes da Rocha, Shengjing Shi, Heejung Cho, Ulas Karaoz, Dominique Loqué, Benjamin P Bowen, Mary K Firestone, Trent R Northen, Eoin L Brodie
Like all higher organisms, plants have evolved in the context of a microbial world, shaping both their evolution and their contemporary ecology. Interactions between plant roots and soil microorganisms are critical for plant fitness in natural environments. Given this co-evolution and the pivotal importance of plant-microbial interactions, it has been hypothesized, and a growing body of literature suggests, that plants may regulate the composition of their rhizosphere to promote the growth of microorganisms that improve plant fitness in a given ecosystem...
April 2018: Nature Microbiology
Yangzhuo He, Yujia Xiang, Yaoyu Zhou, Yuan Yang, Jiachao Zhang, Hongli Huang, Cui Shang, Lin Luo, Jun Gao, Lin Tang
Selenium (Se) contamination in surface and ground water in numerous river basins has become a critical problem worldwide in recent years. The exposure to Se, either direct consumption of Se or indirectly may be fatal to the human health because of its toxicity. The review begins with an introduction of Se chemistry, distribution and health threats, which are essential to the remediation techniques. Then, the review provides the recent and common removal techniques for Se, including reduction techniques, phytoremediation, bioremediation, coagulation-flocculation, electrocoagulation (EC), electrochemical methods, adsorption, coprecipitation, electrokinetics, membrance technology, and chemical precipitation...
March 16, 2018: Environmental Research
Rong Hao, Jinliang Zhang, Peichao Wang, Ronggui Hu, Yantun Song, Yupeng Wu, Guohong Qiu
Water resources management is an important public concern. In this study, we examined the extent of sorption/desorption of trace pollutants to soil black carbon (BC) in the water level fluctuation zone (WLFZ) of the middle route of the South to North Water Transfer Project in China. In addition, we investigated the main management measures affecting these processes during the project. The results showed that the pseudo second-order model adequately describes the sorption/desorption of phenanthrene on the soil BC in the WLFZ...
March 10, 2018: Journal of Environmental Management
Erika Buscardo, József Geml, Steven K Schmidt, Helena Freitas, Hillândia Brandão da Cunha, Laszlo Nagy
Most tropical evergreen rain forests are characterised by varying degrees of precipitation seasonality that influence plant phenology and litterfall dynamics. Soil microbes are sensitive to soil water:air ratio and to nutrient availability. We studied if within-year seasonality in precipitation and litterfall-derived nutrient input resulted in predictable seasonal variation in soil bacterial diversity/microbial functional groups in an Amazonian forest. We characterised the spatio-temporal dynamics of microbial communities from the plot to the stand scales and related them to precipitation seasonality and spatial variability in soil characteristics...
March 12, 2018: Scientific Reports
Alessandra H Ide, José Manuel F Nogueira
A new hybrid microextraction technique (hollow fiber microextraction) is presented that uses the main concepts and advantages of the modern miniaturized devices used for trace analysis. This novel analytical approach uses devices made of polypropylene membranes (10.0 mm long and 0.6 mm internal diameter) in which convenient organic solvents are embedded that promote fast kinetics during the enrichment process, using the floating sampling technology concept. An innovative analytical cycle is also proposed by use of low-cost disposable devices during the microextraction stage together with a user-friendly ("single liquid desorption step") back-extraction stage in compliance with green analytical chemistry principles...
March 10, 2018: Analytical and Bioanalytical Chemistry
Nicholas Dusek, Austin J Hewitt, Kaycie N Schmidt, Peter W Bergholz
E. coli are deposited into soil with feces and exhibit subsequent population decline with concomitant environmental selection. Environmentally persistent strains exhibit longer survival times during this selection process and some strains have adapted to soil and sediments. A georeferenced collection of E. coli isolates was developed comprising 3,329 isolates from 1,428 soil samples that were collected from a landscape spanning the transition from the grasslands to the eastern deciduous forest biomes. The isolate collection and sample database were analyzed together to discover how land cover, site characteristics and soil chemistry influence the prevalence of cultivable E...
March 9, 2018: Applied and Environmental Microbiology
Lucia Škulcová, Kerstin E Scherr, Lukáš Chrást, Jakub Hofman, Lucie Bielská
The fate of organic chemicals and their metabolites in soils is often investigated in model matrices having undergone various pre-treatment steps that may qualitatively or quantitatively interfere with the results. Presently, effects associated with soil sterilization by γ-irradiation and soil spiking using an organic solvent were studied in one freshly spiked soil (sterilization prior to contamination) and its field-contaminated (sterilization after contamination) counterpart for the model organic compound 1,1-Dichloro-2,2-bis(4-chlorophenyl)ethene (p,p'-DDE)...
March 3, 2018: Ecotoxicology and Environmental Safety
D B Abdala, P A Moore, M Rodrigues, W F Herrera, P S Pavinato
Whereas soil test information on the fertility and chemistry of soils has been important to elaborate safe and sound agricultural practices, micro-scale information can give a whole extra dimension to understand the chemical processes occurring in soils. The objective of this study was to evaluate the effects that the consecutive application of untreated poultry litter, alum-treated litter or ammonium nitrate (NH4 NO3 ) had on P solubility in soils over 20 years. For this, we used soil test data, sequential chemical fractionation (SCF) of P, and P K-edge XANES and μ-fluorescence spectroscopies...
February 28, 2018: Journal of Environmental Management
Youngyun Park, Yongje Kim, Seung-Ki Park, Woo-Jin Shin, Kwang-Sik Lee
Irrigation return flow can include contaminants derived from agricultural practices, and then deteriorate the quality of surface and subsurface water within the watershed. Thus, it is important to estimate the effect of irrigation return flow on water chemistry/quality. To do that water samples were collected between November 2004 and December 2005 from stream and groundwater in a small watershed that contains extensive rice paddy fields. The water isotopic compositions represented seasonal variation, particularly in downstream of main channel and the tributary...
February 27, 2018: Science of the Total Environment
B L Ehlmann, K S Edgett, B Sutter, C N Achilles, M L Litvak, M G A Lapotre, R Sullivan, A A Fraeman, R E Arvidson, D F Blake, N T Bridges, P G Conrad, A Cousin, R T Downs, T S J Gabriel, R Gellert, V E Hamilton, C Hardgrove, J R Johnson, S Kuhn, P R Mahaffy, S Maurice, M McHenry, P-Y Meslin, D W Ming, M E Minitti, J M Morookian, R V Morris, C D O'Connell-Cooper, P C Pinet, S K Rowland, S Schröder, K L Siebach, N T Stein, L M Thompson, D T Vaniman, A R Vasavada, D F Wellington, R C Wiens, A S Yen
The Mars Science Laboratory Curiosity rover performed coordinated measurements to examine the textures and compositions of aeolian sands in the active Bagnold dune field. The Bagnold sands are rounded to subrounded, very fine to medium sized (~45-500 μm) with ≥6 distinct grain colors. In contrast to sands examined by Curiosity in a dust-covered, inactive bedform called Rocknest and soils at other landing sites, Bagnold sands are darker, less red, better sorted, have fewer silt-sized or smaller grains, and show no evidence for cohesion...
December 2017: Journal of Geophysical Research. Planets
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