Investigation on potential of few eucalypt species for absorbing pollutants and reserv-ing them in their leaves

Trees as alive components of an ecosystem are able to convert some of the environment contaminants to unharmful substances and store some of them in their tissues and reduce their density and intensity in the air and soil by breath, root absorption and photosynthesis and other biotic functions. Trees function in such condition is completely related to environmental and habitat circumstances and their physiological potential. At beginning, five research sites at Khuzestan and Bushehr provinces were selected among the contaminated area by the Gulf War. At each site, soil sampling was made from three levels of depth (0-20, 20-40 and 40-60 cm). Soil physical and chemical characteristics test was made to measure nine metal elements and 12 other soil properties. The eucalypt species consisted of: E. camaldulensis, E. camaldulensis 9616, E. microtheca and E. sargentii which were planted under the Randomized Complete Blocks statistical design with three replicates. Before sampling the trees for determining the contaminant elements. Three individual trees were selected at each plot per one replicate to make sampling for leaf (four specimens per tree at four mean geographical directions). The data were analyzed under the variance analysis and Duncan test programs, using Excel and SAS computer soft wares. Overall, amount of the contaminants in different sites and at three levels of depth was not significantly different. The best eucalypt species and the best sites for absorbing the contaminants in their leaves are respectively as follows: 1-       E. camaldulensis, E. microtheca, E. sargentii and E. camaldulensis 9616 2-       Dezful, Isvand, Shooshtar, Karkheh and Kaki. The species which made the best performance in relation to their site interaction are respectively as follows: 1-         E. microtheca firstly at Karkheh and shooshtar sites and secondly at Dezful and Isvand sites. 2-                        E. camaldulensis 9616 3-                        E. camaldulensis and E. sargentii