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Comparison of N and C dynamics in two Norway spruce stands using a process oriented simulation model
1998
Eckersten, H. | Beier, C. (Swedish University of Agricultural Sciences, P.O. Box 7043, S-75007 Uppsala (Sweden))
Modelling the effects of nitrogen addition on soil nitrogen status and nitrogen uptake in a Norway spruce stand in Denmark
1998
Beier, C. | Eckersten, H. (RISO National Laboratory, P.O. Box 49, DK-4000 Roskilde (Denmark))
Effects of nitrogen deposition on tree growth and soil nutrients in boreal scots pine stands
1998
Nissinen, A. | Hari, P. (Department of Forest Ecology, P.O. Box 24, University of Helsinki, 00014 Helsinki (Finland))
Turnover of carbon and nitrogen in coniferous forest soils of different N-status and under different 15NH4-N application rate
1998
Sjoberg, R.M. | Persson, T. (Department of Ecology and Environmental Research, Swedish University of Agricultural Sciences, P.O. Box 7072, S-750 07 Uppsala (Sweden))
Nitrate leaching in forest ecosystems is related to forest floor C/N ratios
1998
Gundersen, P. | Callesen, I. | Vries, W. de (Danish Forest and Landscape Research Institute, Hoersholm Kongevej 11, DK-2970 Hoersholm (Denmark))
Nitrogen saturation experiments (NITREX) in coniferous forest ecosystems in Europe: a summary of results
1998
Tietema, A. | Boxman, A.W. | Bredemeier, M. | Emmett, B.A. | Moldan, F. | Gundersen, P. | Schleppi, P. | Wright, R.F. (University of Amsterdam, Netherlands Centre for Geo-Ecological Research, Nieuwe Prinsengracht 130, NL1018 VZ Amsterdam (Netherlands))
Polycyclic Aromatic Hydrocarbons in the Sediments of the Milwaukee Harbor Estuary, Wisconsin, U.S.A
1998
Li, An | Ab Razak, Irwan A. | Ni, Fan | Gin, Michael F. | Christensen, Erik R.
From 1990 to 1994, a total of 21 sediment cores and 37 grab sediment samples were collected from the Milwaukee Harbor Estuary. Each sediment core was sectioned and dated using ²¹⁰Pb and¹³⁷ Cs radioisotope techniques. A total of 305 samples were analyzed for sixteen polycyclic aromatic compounds (PAHs). Grain size distribution, porosity, and total organic carbon content as measured by loss on ignition were also determined. The results provide a historical overview of the impact of industrialization in the Milwaukee area. Although highly variable, the concentration profile of PAHs show, in general, peaks in the 1950's through 1980's. The PAH concentrations have declined since then for most sediment cores. The current levels of total PAHs in most surface sediment samples range from 25 to 200 ppm. A few cores, some of which were collected in 1994, have an elevated PAH concentration at the surface. Toxicity of the surface sediments was evaluated by comparing with the benchmark values developed by the United States National Oceanic and Atmospheric Administration (NOAA). The most heavily contaminated area was found in the Kinnickinnic River between the Becher Street Bridge and the Wisconsin Wrecking Company Wharf. The highest total PAH concentration determined from seven vibra cores collected in this area ranges from 380 to 1000 ppm. The former Wisconsin Solvay Coke Company may have been a major point source of PAHs until the 1970's. Highway traffic and various industrial discharges also contribute to the sediment PAHs in this area.
Show more [+] Less [-]Sulfate adsorption-desorption in a Swedish forest soil
1998
Gobran, G.R. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research) | Selim, H.M. | Hultberg, H. | Andersson, I.
