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Direct and Indirect Effects and the Long-term Risks of Climate Change on Forests: Carbon Balances in United Kingdom Forests
1993
Jarvis, P.G. (University of Edinburgh, Scotland (United Kingdom). Institute of Ecology and Resource Management)
The area of productive woodland in the UK has been increasing steadily since 1950, generally at about 20-30 thousand hectares per year. The current forest estate covers 2,1 million hectares, the annual growth in the total stored carbon in wood is 2,0 million tonnes. The annual UK output of carbon dioxide from the burning of fossil fuels is 162 million tonnes.
显示更多 [+] 显示较少 [-]Direct and Indirect Effects and the Long-term Risks of Air Pollution on Forest Ecosystems: A Call for Caution in Proper Diagnosis of Causes
1993
Skelly, J.M. (The Pennsylvania State University, (USA). Department of Plant Pathology)
Forest Scientists must recognize that numerous diseases and insect occurrences as well as more subtle environmental stresses are prevalent as causes of changes in forest health. Their interactions often lead to "natural" declines of individual tree species or site-species declines of multiple species. The role of air pollution should be carefully investigated in an integrative sense with these other endemic and sometimes epidemic outbreaks of biotic agents and environmental stresses.
显示更多 [+] 显示较少 [-]Direct Effects of Air Pollution on Forest Ecosystems of Western North America
1993
Peterson, D.L. (University of Washington, Seattle (USA))
Visible chlorotic injury and reduced foliar biomass are found in Pinus ponderosa and P. jefreyi in the mountains of southern California and the west slope of Sierra Nevada. Reduced tree growth and accelerated rates of forest succession has been documented in this area, with ozone resistant, shade tolerant species replacing P. ponderosa. There may also be some interactions among ozone, drought stress, insects and fungal pathogens.
显示更多 [+] 显示较少 [-]Direct and Indirect Effects and the Long-term Risks of Climate Change on Forests: Tropical Deforestation and Carbon Dioxide
1993
Jarvis, P.G. (University of Edinburgh, Scotland (United Kingdom). Institute of Ecology and Resource Management)
Destruction of forests leads to the release of carbon dioxide stored in the wood and also usually results in major releases of carbon dioxide stored in soil. Annual releases of carbon dioxide from destruction of tropical forests was estimated at about 1650 million tonnes per year.
显示更多 [+] 显示较少 [-]Direct Effects of Air Pollution on Physiology of Forest Trees in the Western United States
1993
Bytnerowicz, A. (USDA Forest Service, Riverside, CA (USA). Pacific Southwest Research Station)
Physiological processes of western trees are effected by ozone at concentration over 80 ppb, depending on the duration of the exposures and environmental conditions. At a single fascicle level short-term ozone exposures can cause reduction, no change or increase of stomatal conductance and net assimilation rate. Two seasons of exposures at twice level ozone concentrations caused a significant reduction of stomatal conductance and pigment concentrations in foliage.
显示更多 [+] 显示较少 [-]Direct and indirect effects and the long term risks of air pollution on forest ecosystems: economic risks involved in forest devastation through air pollution and climate change
1993
Schulz, H. (University of Munich (Germany). Institute for Wood Research)
Wood will have a great importance as renewable raw material. Forest devastation endangers the world's future wood supply. We need a long-term strategy for forestry and forest products industries to protect complete ecological life cycle.
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 [-]General summary and synthesis | [Resume general et synthese] | [Resumen general y sintesis]
1993
Innes, J.L. | Schlaepfer, R. | Bucher, H.P. (Swiss Federal Institute for Forest Snow and Landscape Research, Birmensdorf (Switzerland)) | Kraeuchi, N. (Swiss Federal Institute for Technology, Zurich (Switzerland))
The report summarizes scientific information about forest ecosystems and their relationship to climate change and air pollution, with special emphasis on forests in Europe, North America and China. The contributions reflect the current state of science, but also uncertainties and gaps in scientific knowledge.
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.
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