Evaluating and planning waste landfill top covers with the help of vegetation and population ecology

摘要

The accumulation of solid waste has caused remarkable problems for environment and public health, and authorities have to tackle the costly recycling, reduction, and management of solid waste. Nevertheless, the area occupied by landfills is steadily growing. It is an urgent need to avoid toxic impacts such as landfill gas or leachate arising from old landfills, and to find environmentally friendly after-uses for the sites. The cooperation of waste management and botany shows viable practices for the future: Phytosociological releves of the (spontaneous or seeded) vegetation on old landfills can indicate not only the quality of the top cover, but also gaps in the cover where methane or leachate emerge. This information helps companies and authorities to take appropriate steps of sanitation. Well-kept old landfills may be re-integrated into the production of energy plants or fibre plants. Another possible after-use would be a park for recreation. In this case, special care has to be taken for selecting local tree and shrub species with suitable demands and a superficial root system. In regions where rare ecosystems in the vicinity of a landfill are threatened by extinction, one can think of a reestablishment of those ecosystems. By providing a suitable top cover and introducing species of the threatened ecosystem, it is possible to trigger a succession towards this. Nevertheless, steady monitoring of the vegetation development and the soil seed bank is necessary to guarantee success. A new experimental field for botanists and ecological engineers is re-vegetation on combustion slag. To reduce the volume of waist, some municipalities have chosen this method recently instead of mechanical-biological waste treatment. Recultivating combustion slag causes many ecological problems, and this is one of the challenges for the future.