نتایج جستجو برای: nutrient concentrations

تعداد نتایج: 366923  

Journal: :Plant physiology 1971
J E Leggett

Soybean plants (Glycine max L. Merr. var. Hawkeye), grown in nutrient solutions maintained at graded concentrations showed a large response in both shoot dry weight and total ion uptake. Growth rate was dependent upon nutrient concentration, even when quantity of nutrient was not limiting. Peak periods for absorption of specific ions at certain growth stages were not exhibited. Rates of ion upt...

Journal: :Global change biology 2017
Jordi Sardans Mireia Bartrons Olga Margalef Albert Gargallo-Garriga Ivan A Janssens Phillipe Ciais Michael Obersteiner Bjarni D Sigurdsson Han Y H Chen Josep Peñuelas

Plant invasion is an emerging driver of global change worldwide. We aimed to disentangle its impacts on plant-soil nutrient concentrations. We conducted a meta-analysis of 215 peer-reviewed articles and 1233 observations. Invasive plant species had globally higher N and P concentrations in photosynthetic tissues but not in foliar litter, in comparison with their native competitors. Invasive pla...

2015
Willem A Gericke

At first, laboratory-scale work under aerobic conditions was undertaken on bacteria imported from the USA. The system was optimised for variables including pH, temperature, nutrient type (e.g. glucose, molasses) and nutrient addition rate. As the effluent could contain phenols, tolerance to phenols at different concentrations was also investigated, including the possibility of utilising phenol ...

Journal: :Journal of environmental quality 2008
Todd V Royer Mark B David Lowell E Gentry Corey A Mitchell Karen M Starks Thomas Heatherly Matt R Whiles

Nutrient enrichment is a frequently cited cause for biotic impairment of streams and rivers in the USA. Efforts are underway to develop nutrient standards in many states, but defensible nutrient standards require an empirical relationship between nitrogen (N) or phosphorus (P) concentrations and some criterion that relates nutrient levels to the attainment of designated uses. Algal biomass, mea...

2008
Bray J. Beltran Devendra M. Amatya Timothy J. Callahan

Intensive plantation forestry will be increasingly important in the next 50 years to meet the high demand for domestic wood in the US. However, forestry management practices can substantially influence downstream water quality and ecology. In this study, the effect of fertilization on drainage water quality of a coastal pine plantation located in Carteret County, NC was studied. The pine planta...

Journal: :Microbiological reviews 1985
D K Button

INTRODUCTION Nutrient-limited growth is the usual state for most microorganisms of the environment. In aquatic systems, nutrients are usually absorbed until concentrations decrease to levels that are sufficient for the growth of only those organisms with good transport systems, or ones that can grow very slowly. Many terrestrial systems are also restricted by nutrient concentrations, because mu...

2006
Jennifer D. Knoepp Barbara C. Reynolds D. A. Crossley Wayne T. Swank

Soil nutrient concentrations decreased in an aggrading southern Appalachian forest over a 20-year period. Construction of nutrient budgets showed significant nutrient sequestration aboveground including increased forest floor mass. We hypothesized that the changes in forest floor mass resulted from decreased litter decomposition rates because of decreased litter quality. In 1992 and 1993, we re...

2012
Tyler J. Kohler Thomas N. Heatherly Rana W. El-Sabaawi Eugenia Zandonà Michael C. Marshall Alexander S. Flecker Catherine M. Pringle David N. Reznick Steven A. Thomas

Light, nutrient availability, and flow are strong factors controlling the elemental composition and biomass of epilithon in temperate stream ecosystems. However, comparatively little is known about these relationships in tropical streams. We investigated how gradients of light and nutrient availability, seasonality, and habitat influenced epilithon biomass, chlorophyll a, and nutrient ratios in...

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