attractants for pollination purposes, for transmittance of seeds 
through edible fruits, or by cultivation for economic purposes 
that is food, medicinal, or industrial use. 
Other compounds socially “protect” by repelling insects, 
fungus, herbivorous animals and man. 
—Thirdly, in the event that the exclusion mechanism fails, or is 
overloaded, extraneous elements are translocated to the canopy, 
where exfoliation effectively provides elimination. 
Hyper-accumulation has a number of promoters: e.g., 
overwhelming of the exclusion mechanism by very high 
concentrations demonstrates itself in geochemical prospecting 
indicators of ore deposits. 
Metabolic disorders brought about about the first notice of 
hyper-accumulators by Agricola in 1467 in DE RE METAL- 
LICA. Agricola described the hyper-accumulators as “sick- 
looking plants”. 
Pathologies of respiration, insect or fungus infestation, and 
tissue degeneration demand the heightened production of the 
necessary remedial compounds. In the event that the remedial 
agent cannot keep up with the disease, we are likely to see, in fact, 
actual deposition of the element at the site of the pathology. 
Stress is also a promoter of hyper-accumulation. Plants have 
been shown to hyper-accumulate as a result of stress induced by 
alternately subjecting the plants to nutrient-rich and nutrient- 
poor growth solutions. 
This factor of environmental stress occurring to all plants ina 
particular ecosystem may display an overall pattern of hyper- 
accumulation as the community seeks to establish itself, 
In response to a reduction in soil pH, and thus increased 
availability of elements for uptake, one would expect a 
corresponding increase in uptake by plants. 
Whatever the elemental accumulation, it becomes a factor in 
the identification of residues and in linking them to their source. 
3) WHAT TYPE OF STRATEGY CAN BE APPLIED 
TO COMPLEMENT THIS RESEARCH? 
Wood and other plant materials such as gums, resins, reeds, 
grasses having use in construction and deposits of foods, 
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