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Long-term effects of pollutants on forest vegetation in Central Spis region
2002
Mankovska, B. (Forest Research Institute, Zvolen (Slovak Republic))
Pollution problems in forest ecosystems resulting from 100 year long operation of three smelter complexes in Central Spis are reviewed. Original data are presented with respect to temporal and spatial trends of nitrogen, sulphur and heavy metal pollution, and elemental composition of individual aerosols on leaf surface. Spruce stands in Central Spis are loaded by pollutants 1.7 times more than are critical values and the highest concentrations of As, Fe, Hg, and N were found in this region. Low Tatra National Park was the cleanest region where no element maxima were found
Afficher plus [+] Moins [-]Foliar elements of Scots pine across the transect from the ammonia emission source (1995-1998)
2002
Kupcinskiene, E. (University of Agriculture of Lithuania, Kaunas (Lithuania). Kaunas-Akademia)
Significant correlations (p0.05) were found between the concentration of elements in the c needles and the distance of the sites from nitrogen ferilizer factory (NFF): the amounts of C, K, Mg, Zn, and Rb in the c+1 needles were increasing, whereas concentrations of N, P, Al, Mn, Cu, Ni, Sr and Cd were decreasing alongside the transect from NFF. Statistical analyses performed on logarithms and estimation of components of variance by maximum likelihood has shown that the age of the needles and the sites were the most important, while year of sampling was much smaller source of variance. Only a few significant differences were found comparing the amount of elements in Scots pine needles collected in four-year space
Afficher plus [+] Moins [-]Discussion of the effects of N with and without acidified S on a sitka spruce ecosystem after 5 years treatment
2002
Sheppard, L.J. | (CEH Edinburgh Bush Estate, Edinburgh (United Kingdom)) | Crossley, A. | Ingleby, K. | Carfrae, J. | Harvey, F. | Kennedy, V.
Significant differences in the effects of N alone compared with NS Acid have been found with respect to eutrophication and acidification. N alone had no effect on the pleurocarpous mosses, whereas NS Acid caused their death within 2 years. Both treatments enhanced stem area increment and N alone also doubled fine root growth. By contrast NS Acid treatments increased litterfall in a a dose response fashion
Afficher plus [+] Moins [-]Forest health research on a natural air pollution gradient in the San Bernardino Mountains, Southern California
2002
Arbaugh, M.J. | Alonso, R. | Bytnerowicz, A. (USDA Forest Service, Riverside (USA). Pacific Southwest Research Station)
Toxic effects of photochemical smog on ponderosa and Jeffrey pines in the San Bernardino Mountains were discovered in the 1950s. It was revealed that ozone is the main cause of foliar injury manifested as chlorotic mottle and premature needle senescence. Various morphological, physiological and biochemical alterations in the affected plants have been reported over a period of about 40 years of multidisciplinary research. Recently, the focus of research has shifted from studying the effects of ozone to multiple pollutant effects. Recent studies have indicated that the combination of ozone and nitrogen may alter biomass allocation in pines towards that of deciduous trees, accelerate litter accumulation and increase carbon sequestration rates in heavily polluted forests
Afficher plus [+] Moins [-]Ozone symptoms in native herbaceous species in Southern Alps: field assessment and laboratory verification
2002
Gerosa, G. (Universita degli Studi, Milano (Italy). DiProVe) | Marzuoli, R. | Cesana, V. | Ballarin-Denti A. | Bussotti, F.
Small attention has been still addressed to the study of ozone effects on seminatural vegetation. Following this direction we selected an ozone heavily exposed area in Northern Italy, where the development of visible injuries on leaves of common pasture herbs were observed. The selected area, an alpine pasture located at Moggio belongs to the Level II permanent monitoring network of the ICP-Forest program. The ozone exposure mapping exercise made on the whole regional domain estimated for this area an AOT40f of 32000 ppb.h as 1999 and 2000 years average
Afficher plus [+] Moins [-]Long-term effects of air pollution on spruce forests in the Tatra Mts. - ozone and vegetation studies
2002
Godzik, B. (Polish Academy of Sciences, Krakow (Poland). Institute of Botany) | Fleischer, P. | Grodzinska, K.
Wet-deposited - sulphur and nitrogen pollutants and ambient ozone are important anthropogenic factors affecting forest health. Regular assessment of chemistry of throughfall and precipitation water based on two-week sampling started in 1997. Passive samplers for detection of ozone concentration have been exposed on a network of monitoring stations during vegetation periods since 1998. In addition, in selected locations, UV absorption monitors for continuous O3 measurements were installed in 1999
Afficher plus [+] Moins [-]Ponderosa pine response to elevated CO2 and nitrogen
2002
Johnson, D.W. (University of Nevada, Reno (USA). Environmental and Resource Sciences) | Ball, J.T. | Hoylman, A.M. | Walker, R.F.
This paper summarizes the data on growth response and N uptake in open-top chambers planted with ponderosa pine (Pinus ponderosa Laws.) treated with both N (0, 10, and 20 g N msub-2 yrsub-1 as ammonium sulfate ) and CO2. Both N and elevated CO2 caused increased growth. The effects of N on growth response to elevated CO2 were assessed in various ways and various interpretations could be drawn depending on which metric was used, including a negative effect of N on growth response to CO2. These calculations suggest that expressing growth as percentages can be misleading, especially when done on a grams per tree basis
Afficher plus [+] Moins [-]Vertical flow constructed wetlands subject to load variations : an improved design methodology connected to outlet quality objectives. | Filtres plantés de roseaux soumis à variation de charges : quel dimensionnement pour quel objectif de qualité ?
2014
Boutin, Catherine | Prost Boucle, S.
This study set out to assess how vertical flow constructed wetlands (vfCW) adapt to different types of tourism-driven variations in influent load, i.e. (i) campsites, closed for six months of the year and featuring a two-month-only window of high-season activity, and (ii) tourist-interest villages either hosting tourists over at least the six months of summer while the permanent population is resident or summer festivals that create intense pollution loads in a short burst of just a few days. The study surveyed 4 campsites and 4 tourist-interest villages that were monitored for several years, generating over 70 performance balances for vfCW that were intentionally scaled down in relation to the conventional French design for experimental trials. The influent wastewater effectively qualifies as domestic sewage, although relatively concentrated, with the campsites presenting particularly high nitrogen concentrations (122 gTKN.L-1). The applied daily loads were also particularly high, with some combinations of load parameters (hydraulic load, organic matter, TKN) leading to 400% overloading. Even under these drastic conditions, quality of effluent remained excellent on the characteristic organic matter parameters, with removal performances always over 85%. However, nitrification performances were poor to good. Analysis of the dataset points to two major design thresholds: For campsites, in order to keep a 73% nitrification rate even at the height of the summer season, the load applied to the 1st stage filter in operation has to be capped at less than 600 gCOD.m-².d-1. For tourist-interest villages, in order to keep an 85% nitrification rate in the summer season, the load applied to the 2nd stage filter in operation has to be capped at less than 22 gTKN.m-².d-1. Here, vfCW were demonstrated to robustly handle a massive increase in loads applied, providing the wetland construction and operation stringently follow best design standards and practices.
Afficher plus [+] Moins [-]Blood mercury concentrations in four sympatric gull species from South Western France: Insights from stable isotopes and biologging
2022
Jouanneau, William | Sebastiano, Manrico | Rozen-Rechels, David | Harris, Stephanie M. | Blévin, Pierre | Angelier, Frédéric | Brischoux, François | Gernigon, Julien | Lemesle, Jean-Christophe | Robin, Frédéric | Cherel, Yves | Bustamante, Paco | Chastel, Olivier
Mercury (Hg) is a toxic trace element widely distributed in the environment, which particularly accumulates in top predators, including seabirds. Among seabirds, large gulls (Larus sp) are generalist feeders, foraging in both terrestrial and marine habitats, making them relevant bioindicators of local coastal Hg contamination. In the present study, we reported blood Hg concentrations in adults and chicks of four different gull species breeding on the French Atlantic coast: the European herring gull (Larus argentatus), the Lesser black-backed gull (L. fuscus), the Great black-backed gull (L. marinus) and the Yellow-legged gull (L. michahellis). We also investigated the potential role of foraging ecology in shaping Hg contamination across species, using the unique combination of three dietary tracers (carbon, nitrogen and sulfur stable isotopes) and biologging (GPS tracking). A high concentration of Hg was associated with high trophic position and a marine diet in gulls, which was corroborated by birds’ space use strategy during foraging trips. Adults of all four species reached Hg concentrations above reported toxicity thresholds. Specifically, adults of Great black-backed gulls had a high trophic marine specialized diet and significantly higher Hg concentrations than the three other species. Blood Hg was 4–7 times higher in adults than in chicks, although chicks of all species received mainly marine and high trophic position prey, which is expected to be the cause of blood Hg concentrations of toxic concern. By using both stable isotopes and GPS tracking, the present study provides compelling insights on the main feeding habits driving Hg contamination in a seabird assemblage feeding in complex coastal environments.
Afficher plus [+] Moins [-]Combined biochar and double inhibitor application offsets NH3 and N2O emissions and mitigates N leaching in paddy fields
2022
He, Tiehu | Yuan, Junji | Xiang, Jian | Lin, Yongxin | Luo, J. (Jiafa) | Lindsey, S. B. (Stuart B.) | Liao, Xia | Liu, Deyan | Ding, Weixin
The effects of combined biochar and double inhibitor application on gaseous nitrogen (N; nitrous oxide [N₂O] and ammonia [NH₃]) emissions and N leaching in paddy soils remain unclear. We investigated the effects of biochar application at different rates and double inhibitor application (hydroquinone [HQ] and dicyandiamide [DCD]) on NH₃ and N₂O emissions, N leaching, as well as rice yield in a paddy field, with eight treatments, including conventional urea N application at 280 kg N ha⁻¹ (CN); reduced N application at 240 kg N ha⁻¹ (RN); RN + 7.5 t ha⁻¹ biochar (RNB1); RN + 15 t ha⁻¹ biochar (RNB2); RN + HQ + DCD (RNI); RNB1 + HQ + DCD (RNIB1); RNB2 + HQ + DCD (RNIB2); and a control without N fertilizer. When compared with N leaching under RN, biochar application reduced total N leaching by 26.9–34.8% but stimulated NH₃ emissions by 13.2–27.1%, mainly because of enhanced floodwater and soil NH₄⁺-N concentrations and pH, and increased N₂O emission by 7.7–21.2%, potentially due to increased soil NO₃⁻-N concentrations. Urease and nitrification inhibitor addition decreased NH₃ and N₂O emissions, and total N leaching by 20.1%, 21.5%, and 22.1%, respectively. Compared with RN, combined biochar (7.5 t ha⁻¹) and double inhibitor application decreased NH₃ and N₂O emissions, with reductions of 24.3% and 14.6%, respectively, and reduced total N leaching by up to 45.4%. Biochar application alone or combined with double inhibitors enhanced N use efficiency from 26.2% (RN) to 44.7% (RNIB2). Conversely, double inhibitor application alone or combined with biochar enhanced rice yield and reduced yield-scaled N₂O emissions. Our results suggest that double inhibitor application alone or combined with 7.5 t ha⁻¹ biochar is an effective practice to mitigate NH₃ and N₂O emission and N leaching in paddy fields.
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