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Full-Text Articles in Life Sciences
Effects Of Nitrogen On Temporal And Spatial Patterns Of Nitrate In Streams And Soil Solution Of A Central Hardwood Forest, Frank S. Gilliam, Mary Beth Adams
Effects Of Nitrogen On Temporal And Spatial Patterns Of Nitrate In Streams And Soil Solution Of A Central Hardwood Forest, Frank S. Gilliam, Mary Beth Adams
Frank S. Gilliam
This study examined changes in stream and soil water NO3−and their relationship to temporal and spatial patterns of NO3−in soil solution of watersheds at the Fernow Experimental Forest, West Virginia. Following tenfold increases in stream NO3−concentrations over a 13-year period (1969–1981) on untreated WS4, concentrations have declined through 2006. Followingfourfold increases in stream NO3−on treatment WS3 from pretreatment levels to a 1998 maximum, concentrations have declinedthrough 2006, despite additions of N. Concentrations of soil water NO3−were consistently lower for WS4 compared to WS3.Data for soil water NO3−on WS3 versus WS4 followed patterns of net mineralization and nitrification for these watersheds.Nitrogen …
Effects Of In Situ Freezing On Soil Net Nitrogen Mineralization And Net Nitrification In Fertilized Grassland Of Northern China, X. Zhang, W. Bai, Frank S. Gilliam, Q. Wang, X. Han, L. Li
Effects Of In Situ Freezing On Soil Net Nitrogen Mineralization And Net Nitrification In Fertilized Grassland Of Northern China, X. Zhang, W. Bai, Frank S. Gilliam, Q. Wang, X. Han, L. Li
Frank S. Gilliam
Effects of soil freezing on nitrogen (N) mineralization have been the subject of increased attention in the ecological literature, though fewer studies have examined N mineralization responses to successive mild freezing, severe freezing and cyclic freeze–thaw events. Even less is known about relationships of responses to soil N status. This study measured soil N mineralization and nitrification in the field along an experimental N gradient in a grassland of northern China during the dormant season (October 2005–April 2006), a period in which freezing naturally occurs. Net N mineralization exhibited great temporal variability, with nitrification being the predominant N transformation process. …
Factors Influencing Spatial Variability In Nitrogen Processing In Nitrogen-Saturated Soils, Frank S. Gilliam, Charles C. Somerville, Nikki L. Lyttle, Mary Beth Adams
Factors Influencing Spatial Variability In Nitrogen Processing In Nitrogen-Saturated Soils, Frank S. Gilliam, Charles C. Somerville, Nikki L. Lyttle, Mary Beth Adams
Frank S. Gilliam
Nitrogen (N) saturation is an environmental concern for forests in the eastern U.S. Although several watersheds of the Fernow Experimental Forest (FEF), West Virginia exhibit symptoms of Nsaturation, many watersheds display a high degree of spatial variability in soil N processing. This study examined the effects of temperature on net N mineralization and nitrification in N-saturatedsoils from FEF, and how these effects varied between high N-processing vs. low N-processingsoils collected from two watersheds, WS3 (fertilized with [NH4]2SO4) and WS4 (untreated control). Samples of forest floor material (O2 horizon) and mineral soil (to a 5-cm depth) were taken from three subplots …