Affiner votre recherche
Résultats 181-190 de 281
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.
Afficher plus [+] Moins [-]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.
Afficher plus [+] Moins [-]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.
Afficher plus [+] Moins [-]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.
Afficher plus [+] Moins [-]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.
Afficher plus [+] Moins [-]Ecology and pollution of Ganga River
1993
Khanna, Dev Raj
Climate Change and Forest Ecosystems - an Overview
1993
Kraeuchi, N. (Swiss Federal Institute of Technology, Zurich (Switzerland). Department of Forest and Wood Research)
Climate change must be considered an ecological and socio-economic threat. We have to support any measures that are combating climate change. It is currently unknown which climate scenario will come true, and therefore very important to maintain the biological diversity of the forest ecosystems for a wide variety of possible development.
Afficher plus [+] Moins [-]