The direct emission of organic acids (acetic, formic and pyruvic) and carbonyl compounds (pyruvate, formaldehyde, acetaldehyde, acetone, propionaldehyde, methacrolein, and methyl ethyl ketone) from soil and a cottonwood tree nearby were investigated using dynamic enclosure methods during the summer of 2005. Ambient air concentrations close to the sample sites (soil and tree) were also identified and quantified for correction purposes. The site of study was Socorro New Mexico. Organic acids were captured in a nebulizer, and analyzed by ion chromatography; carbonyl compounds were captured in a C18-cartridge coated with 2,4 dinitro-phenylhydrazine and analyzed by high performance liquid chromatography. The average ambient concentrations of total organic acids and total carbonyl compounds were 8.22 ± 5.57 ppbv and 5.43 ± 2.59 ppbv respectively. For tree emissions the average concentrations for total organic acids and total carbonyl compounds were 18.25 ± 17.72 ppbv (533.62 ± 432.55 ng/g/hr where g stands for grams of dry leaves) and 11.31 ± 9.01 ppbv (2000 ± 1280 ng/g/hr). For the soil study the average emission rate for carbonyl and organic acid compounds were 32.17 ± 57.67 ng/m2/min and 105.79 ± 99.06 ng/m2/min respectively. Formaldehyde and acetaldehyde were the major emissions of carbonyl compounds and formic and acetic acids were the major emissions of organic acids for the tree, ambient and soil. Formaldehyde, acetaldehyde, formic acid and acetic acid were also the dominant species in the ambient samples.