lead and cadmium concentrations in throughfall of pinus eldarica

this research was carried out in order to quantify throughfall (tf) and interception loss (i) and to compare the chemical composition of tf, i.e. lead (pb) and cadmium (cd) as well as electrical conductivity (ec) and ph beneath pinus eldarica and cupressus arizonica plantations and the open field rainfall. the research was accomplished in the chitgar forest park, a semi-arid polluted urban area, around tehran, iran. gross rainfall (gr) was measured using ten collectors located in an open field. tf was quantified by randomly manual tf collectors placed beneath each plantation. measurements were recorded on an event basis from 15 april 2010 to 15 february 2011. during the measurement, eighteen rainfall events with cumulative gr value of 114.8 mm were recorded. interception loss was 35.3 mm by p. eldarica plantation and 30.4 mm by c. arizonica. there were strong correlations between i:gr and gr ((r2 pinus = 0.686, r2 cupressus = 0.766, p value ? 0.01). pb and cd concentrations as well as ec of tf were significantly different among p. eldarica and c. arizonica and the open field. the results demonstrated that interception represents a considerable portion of gr in p.eldarica and c. arizonica plantations and, therefore, it should be considered while choosing trees for plantations in semiarid climate zones of iran. our results showed that p.eldarica and c. arizonica plantations have good potentials for filtering the polluted air with pb and cd.