Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 2/13/2002
Publication Date: 2/13/2002
Citation: HYDER, P.W., FREDRICKSON, E.L., ESTELL, R.E., HAVSTAD, K.M., DONART, G.B. CHANGES IN PHENOLIC COMPOUNDS AND ORGANIC MATTER IN LEAF LITTER FROM CREOSOTEBUSH [LARREA TRIDENTATA (SESS. & MOC. EX DC.) COV.] AND TARBUSH (FLOURENSIA CERNUA DC.). 55TH ANNUAL MEETING, SOCIETY FOR RANGE MANAGEMENT. 2002. ABSTRACT P. 13.
Technical Abstract: Creosotebush and tarbush leaf litter contain phenolic compounds that may interact allelopathically with surrounding plants and soil biota. Our objective was to measure decline in phenolic concentrations with time. We placed fiberglass bags (1mm mesh) of litter beneath creosotebush and tarbush canopies. One set (two bags) was placed on the soil surface and one set was buried at 5 cm. Bags (six replicates, two duplicates) were collected at 0, 1, 3, 5, 7, 11, 15, 22, 30, 45, 60 and 90 days. Sets 1 and 2 (winter creosotebush and tarbush, respectively) were placed from February to April. Set 3, spring creosotebush, was placed from April to July. Set 1 lost organic matter at the rate of 0.000525 and 0.00406 mg/day; total phenolics, 0.209 and 0.111 mg/day; and, condensed tannins, 0.579 and 0.385 mg/day for surface and buried, respectively. Set 2 lost organic matter (0.00255 and 0.00392 mg/day) and total phenolics (0.449 and 0.517 mg/day) while concentrations of condensed tannins increased (0.0593 and 0.0929 mg/day) for surface and buried samples, respectively. Set 3 lost total phenolics (0.0470 and 0.151), nordihydroguaiaretic acid (0.165 and 0.210), condensed tannins (0.0863 and 0.0891), and organic matter (0.0247 and 0.0570 mg/day) for surface and buried, respectively. Percent organic matter loss was 1.99% and 3.23% for winter creosote, surface and buried samples, respectively; 2.31% surface and 2.49% buried for tarbush; and, 34.10% and 75.27% for surface and buried spring creosote, respectively. We demonstrated that concentrations of phenolic compounds decline in both surface and buried leaf litter.