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Status and Trend of Deposition Rates in Spruce Stands of Baden-Wuerttemberg (Germany)
1993
Hildebrand, E.E. (Forest Research Institute Banden-Wuerttemberg, Freiburg (Germany))
Deposition rates in Baden-Wuerttemberg, which are monitored by sampling grid, mostly exceed critical loads. This applies especially for nitrogen input and the deposition of total acidity. In a periodic inventory of tree nutrition on a basic grid of 4 km, regions abundant and persistent Mg and K deficiency could be identified.
显示更多 [+] 显示较少 [-]Direct and Indirect effects and the Long-term Risks of Air Pollution on Forest Ecosystems in Latin America
1993
Innes, J.L. (Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf (Switzerland))
The biggest problem facing the forest of Latin America is deforestation. Air pollution also constitutes a threat to some forests, and pollution level will increase in the future. Major problem associated with photochemical smogs have been documented in the mountains around Mexico City and Santiago in Chile. Acidic deposition has been identified in some areas and is known to be affecting forest reserves in rural situations.
显示更多 [+] 显示较少 [-]Indirect effects and the Long-term Risks of Air Pollution on Tolerant Hardwood Forest Ecosystems in Central Canada
1993
Morrison, I.K. (Forestry Canada Ontario Region, Sault Ste. Marie (Canada))
There is a strong evidence to indicate that sulphates and nitrogen oxides cause increased leaching of base cations, principally calcium and magnesium from soils supporting old-growth sugar maple forest in central Canada. Sugar maple trees sequester Ca, especially in bark. A site low in exchangeable bases might become less productive, if subjected to prolonged high rates of leaching and full tree harvesting.
显示更多 [+] 显示较少 [-]Direct and Indirect Effects and the Long-term Risks of Air Pollution on Forest Ecosystems: Effects on Soil Nutrition
1993
Guang-Jing Ma | Bai-Zhong Li | Ping Zhang | Jing-shen Liang (Chinese Academy of Forestry, Wan Shou Shan (China). Research Center for Forest Environment)
Atmospheric pollutant can cause direct effects mediated by foliage and indirect effects mediated through soil. Biotic and abiotic factors can confound relationships among nutrient cycling, growth loss and mortality and air pollution. Changes in the soils could result from acidic deposition. Changes could include increased fertility as a result of sulphur and nitrogen input to soils that are deficient in these elements or decreased fertility through ion leaching or mobilization of toxic substances as aluminium.
显示更多 [+] 显示较少 [-]Direct and Indirect Effects and the Long-term Risks of Air Pollution on Forest Ecosystems: Effects on Soil Micro-organisms
1993
Innes, J.L. (Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf (Switzerland))
The soil biota plays a critical part in the functioning of forest ecosystems. Acidification and heavy metals have the greatest direct effects on the soil biota. However pollutants can have indirect effects through their influence on tree root systems. Acidic deposition can decrease the incidence of mycorrhizal infection, but soil pH and concentration of nitrogen and certain forms of sulphur are also important.
显示更多 [+] 显示较少 [-]Socio-economic assessment of global change and air pollution-related forestry damage
1993
de Steiguer, J.E. (USDA Forest Service, Raleigh, North Carolina (USA))
Information on potential forestry losses seems to be crucial to government officials that they can properly assess the costs and benefits of limiting pollution and greenhouse gas emissions. However very few socio-economic assessments of potential losses have been completed.
显示更多 [+] 显示较少 [-]Effects of climate change and atmospheric pollution on forest ecosystems in eastern North America
1993
Hall, J.P. (Forestry Canada, Ottawa (Canada))
Climate change will be the major impact on all forests, included increased risk of large-scale fires, enhanced susceptibility to insects and diseases. Direct effects of air pollution on vegetation include damage to protective surface structures, disturbance of photosynthesis.
显示更多 [+] 显示较少 [-]Air pollution and forests - an overview
1993
Innes, J.L. (Swiss Federal Institute for Forest Snow and Landscape Research, Birmensdorf (Switzerland))
Considerable uncertainty has surrounded the relationship between forest growth and forest declines in Europe. Although growth decreases have been recorded in several years, by the end of the 1980s, increment at many sites had reached a level higher than any previously recorded. Fertilization by carbon dioxide, favourable climatic conditions and better stand management may all have contributed.
显示更多 [+] 显示较少 [-]Pedologic and nutritional aspects of enhanced carbon-dioxide storage in forest ecosystems
1993
Huettl, R.F. (Forestry Dept. Kali and Salz AG, Kassel (Germany))
Enhanced forest growth in combination with relatively high Nitrogen deposition may result in further pedologic and nutritional changes and an even greater destabilisation of forest ecosystems.
显示更多 [+] 显示较少 [-]Direct and indirect effects and the long term risks of air pollution on forest ecosystems: effects and risks on ectomycorrhizae
1993
Brunner, I. (Swiss Federal Institute for Forest Snow and Landscape Research, Birmensdorf (Switzerland))
Two main effects on ectomycorrhizae can be distinguished: direct effects due to a change in the soil chemistry and indirect effects due to a change of the carbohydrate supply from the host trees to the roots.
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