| Popis: |
Plants and ecosystems may be affected adversely by long-term exposure to gaseous pollutants at concentrations that are not harmful to humans and by the deposition of elements (sulfur and nitrogen) that can be both essential nutrients and pollutants. Some pollutant tolerance has evolved during periods of increased pollutant levels, and pollutant-sensitive individuals have become more apparent since sulfur dioxide and nitrogen oxide concentrations have declined in Europe and North America. Current levels of ozone may reduce plant growth in parts of Europe and Asia, especially when they are irrigated, and it is likely to impose critical limitations on future food production in developing countries. |
