Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Wildland Resources

Department name when degree awarded

Forest Science


George E. Hart


In the summer of 1971 a research project was carried out in an attempt to determine the influence of dust and leachates on rainfall quality . Open precipitation collectors , collectors under polyethylene screens, collectors under Douglas-fir (Pseudotsuga menziesii) and juniper (Juniperus scopulorum) , and leaf analyses were used to determine the relative effects of these two processes by which chemicals are incorporated into the rainwater . All samples were analyzed for sodium (Na+) , calcium (Ca++), magnesium (Mg++), potassium (K+) , and available phosphorus. Under the trees , sodium concentrations increased as much as three times the amount found in the open, calcium was 13 to 16 times greater, magnesium concentrations doubled, and potassium increased as much as 50 times that which occurred in the open rainfall. Calcium was the only cation studied in which the leaching process was important. Increased chemical loads of all other cations were mainly due to dust adhering to the tree canopy as wind passed through it and later being washed off by rainwater.