Stable nitrogen isotope ratios of five mussel species from littoral and pelagic areas were investigated with different trophic states in the eutrophic Lake Taihu, the third largest lake in China. Interpopulation variability for these mussels was relatively small in foot tissues because of the slow turnover time. Seasonal and spatial variations among the delta (15)N values of mussels might be du...

Abstract This study identified drivers of change in Barnegat Bay–Little Egg Harbor Estuary, NJ, USA over multiple long-term time periods by developing an assessment tool (an “Eutrophication Index”) capable of handling data gaps and identifying the condition of and relationships between ecosystem pressures, ecosystem state, and biotic responses. The Eutrophication Index integrates 15 indicators ...

Extensive network of tile drains present in the Midwest USA accelerate losses of nutrients to receiving ditches, rivers and eventually to the Gulf of Mexico. Nutrient inputs from agricultural watersheds and their role in affecting water quality have received increased attention recently; however, benthic sediment-nutrient interactions in tile-fed drainage ditches is still a matter of active res...

We carried out 2 experimental simulations in which natural planktonic communities were subjected to a combination of turbulence and variable nutrient forcing. Nutrient addition was varied both in terms of total nutrient load and in the balance of elements. Unbalanced nutrient inputs (with regard to Redfield values) and varying nitrogen sources are frequent in coastal areas heavily exposed to hu...

sulfur (s) is an essential macronutrient influencing plant growth, nutrient efficiency, quality and health of agricultural crops. the purpose of this research was to study the effects of s rates and sources on growth and fruit quality of apple (malus domestica l.) trees of ‘golden delicious’ at west azerbaijan, iran. experiment was conducted during four seasons (2003-2007), using a factorial ra...

background: investigating the performance of naturally operated treatment plants may be due to the fact that they cannot be operated as desired, or that they should be modified to achieve good performance e.g. for nutrients removal. the advantage of kinetic coefficient determination is that the model can be adjusted to fit data and then used for analyzing alternatives to improve the process. th...

Licorice, Glycyrrhiza glabra Linn., is one of herbal medicines widely used for various purposes, including as a sweetener and for gastric ulcer treatment. However, environmental destruction due to the harvesting of wild licorice is becoming a serious problem. We cultured licorice in a hydroponic system to examine the relation between the concentration of nutritional solution applied and glycyrr...

A survey of numerous field studies shows that nitrogen and phosphorous export coefficients are significantly different across forest, agriculture, and urban land-cover types. We used simulations to estimate the land-cover composition at which there was a significant risk of nutrient loads representative of watersheds without forest cover. The results suggest that at between 20 percent and 30 pe...

A composite model was developed for water and mineral relations of greenhouse tomato (Solanum lycopersicum L.) cultivated in semi-closed or open soilless (rockwool) culture. The model simulated on a daily basis: (i) the evolution of crop leaf area index and water uptake using empirical equations; and (ii) the variations of ion concentrations and electrical conductivity (EC) in the recirculating...

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