Impact of ozone on understory plants of the aspen zone

Journal Article · Fri Jan 01 04:00:00 EST 1971 · Proc., Annu. Meet., Air Pollut. Control Assoc.; (United States)

OSTI ID:5319396

Harward, M R; Treshow, M

The purpose of this study was to learn how ozone might affect the growth and reproduction of understory species of the aspen community, and thereby influence its stability and composition. Plants of 15 representative species of the aspen community were grown in chambers and fumigated 4 hours each day, 5 days per week throughout their growing seasons. These included: Achillea millifolium, Chenopodium album, Chenopodium fremontii, Cruciferae sp., Descurainia pinnata, Descurainia sp., Geranium fremontii, Isatis tinctoria, Ligusticum porteri, Lepidium virginicum, Madia glomerata, Polygonum aviculare, Polygonum douglasii, Phacelia heterophylla, Viola italica. Plants were exposed to 30 pphm, 15 pphm, ambient air reaching 5-7 pphm for 2 hours per day, and filtered air. The study was repeated for 3 seasons. Ambient air caused a significant reduction of total plant weight only of Lepidium virginicum. Six species produced fruit and seeds. At 15 pphm, seed production by Madia glomerata and Polygonum douglasii was significantly reduced. At 30 pphm, seed production was also reduced in Polygonum aviculare and Lepidium virginicum. The two most significant conclusions to emerge from the study were first that several species were more sensitive to ozone than might have been suspected. Second, this sensitivity varied sufficiently that major shifts in community composition would be probable following only a year or two of exposure. More tolerant species have no doubt already become dominant over more sensitive species in natural plant communities exposed to elevated ozone concentrations. It must be stressed that the species studied did not necessarily represent the most ozone sensitive members of the community, or the most tolerant.

• Research Organization: Univ. of Utah, Salt Lake City
• OSTI ID: 5319396
• Report Number(s): CONF-710676-
• Journal Information: Proc., Annu. Meet., Air Pollut. Control Assoc.; (United States), Journal Name: Proc., Annu. Meet., Air Pollut. Control Assoc.; (United States) Vol. 32:6; ISSN PRAPA
• Country of Publication: United States
• Language: English

Related Subjects

560303* -- Chemicals Metabolism & Toxicology-- Plants-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ASPENS
ATMOSPHERES
CONTROLLED ATMOSPHERES
GROWTH
OZONE
PLANT GROWTH
PLANTS
REPRODUCTION
SEEDS
SENSITIVITY
TOXICITY
TREES
WEIGHT