From Cell to Tree

Analysis of the effects of soil toxicity on the level of cells, organs, organisms and ecosystems in view of phytoremediation of polluted soils by woody plants

From Cell…. (exodermis of a fine root under heavy metal stress)

....to Tree (model forest). Photos: M. Goerg-Günthardt (WSL)

The interdisciplinary project "From Cell To Tree" presently comprises of 33 research projects ranging from the molecular level in cells, organs and organisms to complete ecosystems.

Objecitves

Waste deposits in landfills, emissions from industry and agricultural practices together with the use of sewage sludge (regulated in Switzerland since 1981) have led to many areas throughout Europe being contaminated with heavy metals. These problems are not just restricted to localised contaminated sites in need of remediation however, chronic heavy metal contamination over large areas are just as problematic.

The size of the areas which are reckoned to exceed the levels set for heavy metal and organic toxins are 4% (origin agriculture) 12% (Industry), 11% (incinerators) and 9% (traffic) of the potentially agricultural area in Switzerland (Keller & Desaules, Schriftenreihe FAL 23, 1997).

Throughout Europe solutions need to be found to stabilise i.e. decontaminate and use moderately polluted land effectively ('energy farming', recreational areas). For this, data is imperative about rivers, and, regarding the best choice for plant selection, the allocation and ability to metabolise contaminants, soil type and acidity of the rainfall. The major project "From Cell To Tree" demonstrated that the reaction of plants to pollutants can be greatly influenced by competition between the different plant species all of which compete for light, water and nutrients together with associated organisms (pests, pathogens, mycorrhiza, bacteria) A gap has been filled with the results from this project since to date any similar research has been restricted to plants with an economic value (monocultures), potted plants and laboratory tests only.

Aims

• Availability of heavy metal pollutants in plants and associated organisms within a model ecosystem
  
• Influence of acid rain and soil acidity
• Transport and immobilisation of the heavy metals
• Stress physiology (growth, barriers, defense mechanisms, damage)
• Analysis of the relationships under stress, between plants on the one hand (competitiveness) and associated organisms (bacteria, fungi, insects) on the other hand
• Estimating profits and risks of replanting / reforesting moderately contaminated ground
• Phytoremediating dumps

To study the reactions in the field to spontaneous and controlled pests, particularly sucking and feeding insects, the model ecosystems are repreated in 20 field plots near by. Here the plantations are completed by beech, alder (measuring symbiontic N₂ fixation), and maple.

The results from the experimental plots are validated by comparable studies at Swiss field sites with polluted soils.

Content

• Projects
• Experiments
• Meetings
• Poster
• Cooperations

Publications

• List of publications

Contact

• Madeleine S. Goerg-Günthardt