Response of a white clover indicator system to tropospheric ozone at eight locations in the United States

Autor: Thomas W. Dreschel, Grady E. Neely, Allen S. Heagle, William J. Manning, Boris I. Chevone, Joseph E. Miller, C. Lynn Morrison, Patrick M. McCool, Joanne Rebbeck
Rok vydání: 1995
Předmět:
Zdroj: Water, Air, & Soil Pollution. 85:1373-1378
ISSN: 1573-2932
0049-6979
DOI: 10.1007/bf00477173
Popis: A white clover (Trifolium repens L.) system using measured biomass to indicate effective concentrations of tropospheric ozone (O3) has been developed. The system utilizes the relative response of an O3-sensitive clone (NC-S) and an O3-resistant clone (NC-R) grown in 15-liter pots. Forage (leaves, stems and flowers) is cut, dried, and weighed at 28-day intervals. Forage dry weight ratios (NC-S/NC-R) for individual or multiple harvests indicate O3 concentrations during growth. In, 3 years of testing in open-top field chambers at Raleigh, North Carolina, O3 always decreased growth of NC-S more than that of NC-R and the NC-S/NC-R ratio routinely decreased as the O3 concentration increased. A national field test was performed in 1993 and 1994 to determine if the clover system can account for effects of climatic variables on clover growth per-se, and if climatic variables affect the relative response of the two clones to O3. Eight locations (Corvallis, Oregon; Kennedy Space Center, Florida; Delaware, Ohio; Amherst, Massachusetts; Blacksburg, Virginia; Raleigh, North Carolina; Riverside, California; San Bemardino mountains, California) provided large differences in O3 concentrations and climate. The NC-S/NC-R forage ratios for three consecutive 28-day growth periods for each year as related to the mean 12 hour per day O3 concentrations are presented in this manuscript. Ratios were generally highest where mean O3 concentrations were lowest (Oregon and Florida), lowest where mean O3 concentrations were highest (both California locations), and intermediate at other locations.
Databáze: OpenAIRE
Externí odkaz: