Why develop bio-indicators?
Currently no technique to determine the ecotoxicological impact of soil-borne contaminants to trees or landscape flora exists. This means that a significant proportion of expenditure from a reclamation budget is used to clean-up contamination to generic levels. This is unnecessary, environmentally and financially costly, and often leads to a reduced quality of the final landscape. In addition, traditional methods of assessing the phytoavailability of potentially toxic elements in soils are difficult to interpret and are often contradictory.
Forest Research in collaboration with ARUP, aims to develop and refine a biological indicator methodology for assessing the feasibility and risk-benefit of direct vegetation establishment on contaminated land.
The main objectives are:
- To determine whether the ‘indicator’ methodology developed in a nursery environment is effective at predicting the success of vegetation establishment on contaminated sites.
- To determine whether the ‘indicator’ methodology is responsive enough to identify phytoavailable contaminant 'hotspots'.
- To determine whether the ‘indicator’ methodology can effectively be used to test the efficacy of soil amendments at increasing plant growth whilst reducing potentially toxic element (PTE) toxicity
- To test whether the uptake and compartmentation of metals in the biomass of the indicator species can be used as an effective indicator of how other tree species will compartmentalise metal contaminants. If the methodology is successful at meeting this objective it will address two fundamental issues:
- It will determine the viability of phytoremediation technologies at removing or stabilising contaminants
- It will act as an indicator of the risk of contaminants becoming available to primary consumers through the ingestion of plant material containing elevated concentrations of PTEs.
- To provide working examples showing the efficacy of the indicator methodology for reducing waste production and remedial costs of redevelopment works, whilst improving the quality of the final landscape.
This research began in 2003 and is due for completion in 2007.