THE ROLE OF BIOMARKERS IN ENVIRONMENTAL ASSESSMENT .4. TERRESTRIAL PLANTS

The potential of metabolites, enzymatic processes and changes in plant performance as biomarkers in environmental assessment is reviewed. Bi omarkers may be used as an early warning system of specific or general stress at each biological level, from molecules to ecosystems. The se nsitivity of a species and, thus, the efficiency of a biomarker will d epend on the degree of already present adaptation to environmental str ess and on the homogeneity of the investigated population. Biomarkers for specific environmental stresses are scarce; better known are bioma rkers for environmental stress complexes such as heavy metals, physiol ogical drought and extreme temperature or biomarkers as a reaction on a full scale of environmental stresses. It is argued that a battery of biomarkers is necessary to evaluate chemical hazards to species.