نتایج جستجو برای: soil drainage

تعداد نتایج: 219137  

2007
Marcelo D. Nosetto Esteban G. Jobbágy Carlos M. Di Bella

Plants, by influencing water fluxes across the ecosystem–vadose zone–aquifer continuum, can leave an imprint on salt accumulation and distribution patterns. We explored how the conversion of native grasslands to oak plantations affected the abundance and distribution of salts on soils and groundwater through changes in the water balance in naturally salt-affected landscapes of Hortobagy (Hungar...

2012
Karis J. McFarlane Margaret S. Torn Paul J. Hanson Rachel C. Porras Christopher W. Swanston Thomas P. Guilderson

Forest soils represent a significant pool for carbon sequestration and storage, but the factors controlling soil carbon cycling are not well constrained. We compared soil carbon dynamics at five broadleaf forests in the Eastern US that vary in climate, soil type, and soil ecology: two sites at the University of Michigan Biological Station (MI-Coarse, sandy; MI-Fine, loamy); Bartlett Experimenta...

2000
M. Dust N. Baran G. Errera J. L. Hutson C. Mouvet H. SchaÈfer H. Vereecken A. Walker

LEACHP is a modular package for calculating the one-dimensional vertical water and solute ̄ux in horizontally layered soils under transient conditions. Data from ®eld studies conducted in a sandy soil (Vredepeel, The Netherlands) and in a loamy soil (Weiherbach, Germany) were used by ®ve groups to simulate water ̄ow and bromide and pesticide transport with the LEACHP model. Calibrated outputs w...

2017
Martin Bach Mirjam Diesner Dietlinde Großmann Djamal Guerniche Udo Hommen Michael Klein Roland Kubiak Alexandra Müller Thomas G Preuss Jan Priegnitz Stefan Reichenberger Kai Thomas Matthias Trapp

BACKGROUND In order to assess surface water exposure to active substances of plant protection products (PPPs) in the European Union (EU), the FOCUS (FOrum for the Co-ordination of pesticide fate models and their USe) surface water workgroup introduced four run-off and six drainage scenarios for Step 3 of the tiered FOCUSsw approach. These scenarios may not necessarily represent realistic worst-...

2011
Chuanlun L. Zhang Jinxiang Wang Yuli Wei Chun Zhu Liuqin Huang Hailiang Dong

Branched glycerol dibiphytanyl glycerol tetraethers (bGDGTs) are known as bacterial lipids that occur widely in terrestrial environments, particularly in anaerobic peat bogs and soil. We examined the abundance and distribution of bGDGTs in both core (C) and polar (P) lipid fractions from the water column and surface sediments in the lower Pearl River (PR) and its estuary using two extraction me...

2003
Bart van den Hurk Pedro Viterbo

Results from two land surface models participating in the PILPS 2(e) experiment [the default European Centre for MediumRange Weather Forecasts (ECMWF) scheme and a modified version labeled MECMWF] are examined. Modifications are implemented in the parameterization of snow sublimation, albedo ageing, surface runoff, and soil hydraulical coefficients. Results of a third run, SECMWF, in which the ...

Journal: :Journal of environmental quality 2007
Robert E Vaughan Brian A Needelman Peter J A Kleinman Arthur L Allen

Agricultural drainage ditches serve as P transport pathways from fields to surface waters. Little is known about the spatial variation of P at the soil-water interface within ditch networks. We quantified the spatial variation of surficial (0-5 cm) soil P within vegetated agricultural ditches on a farm in Princess Anne, MD with an approximately 30-yr history of poultry litter application. Ditch...

2000
G. L. Harris J. A. Catt R. H. Bromilow A. C. Armstrong

This paper describes the Brimstone Farm dataset used for the comparison of pesticide leaching model performance. The tasks set to the modellers are then described. The soil of the site is heavy clay, in which cracks have a major effect on the hydrology. Data are presented for the leaching of isoproturon and mecoprop from two contrasting plots. Contrasting soil moisture states, resulting from di...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1997
G E Likens S L Tartowski T W Berger D G Richey C T Driscoll H G Frank A Klein

Although trifluoroacetate (TFA), a breakdown product of chlorofluorocarbon replacements, is being dispersed widely within the biosphere, its ecological fate is largely unknown. TFA was added experimentally to an upland, northern hardwood forest and to a small forest wetland ecosystem within the Hubbard Brook Experimental Forest in New Hampshire. Inputs of TFA were not transported conservatively...

Journal: :Carbon Balance and Management 2007
Zhengxi Tan Larry L Tieszen Zhiliang Zhu Shuguang Liu Stephen M Howard

BACKGROUND Wildfires are an increasingly important component of the forces that drive the global carbon (C) cycle and climate change as progressive warming is expected in boreal areas. This study estimated C emissions from the wildfires across the Alaskan Yukon River Basin in 2004. We spatially related the firescars to land cover types and defined the C fractions of aboveground biomass and the ...

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