Growth and nutritive quality of Poa pratensis as influenced by ozone and competition

• Published in: Environmental pollution (1987) 2006-07, Vol.142 (1), p.109-115
• Main Authors: Bender, J., Muntifering, R.B., Lin, J.C., Weigel, H.J.
• Format: Article
• Language: English
• Subjects: Achillea millefolium; Air Pollutants - toxicity; air pollution; Animal Feed; Animal, plant and microbial ecology; Anthoxanthum odoratum; Applied ecology; Biological and medical sciences; Biomass; dry matter accumulation; Ecosystem; Ecotoxicology, biological effects of pollution; forage; Fundamental and applied biological sciences. Psychology; General aspects; grasslands; Growth; leaves; Mesocosm; Nutritive quality; nutritive value; Oxidants, Photochemical - toxicity; Ozone; Ozone - toxicity; Plant competition; plant damage; plant growth; Plant Leaves - drug effects; Poa - drug effects; Poa - growth & development; Poa pratensis; Rumex; Rumex acetosa; Seasons; Veronica; Veronica chamaedrys
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2005.09.012

Interspecific plant competition has been hypothesized to alter effects of early-season ozone (O 3) stress. A phytometer-based approach was utilized to investigate O 3 effects on growth and nutritive quality of Poa pratensis grown in monoculture and in mixed cultures with four competitor-plant species ( Anthoxanthum odoratum, Achillea millefolium, Rumex acetosa and Veronica chamaedrys). Mesocosms were exposed during April/May 2000–2002 to charcoal-filtered air + 25 ppb O 3 (control) or non-filtered air + 50 ppb O 3 (elevated O 3). Biomass production was not affected by O 3, but foliar injury symptoms were observed in May 2002. Early-season O 3 exposure decreased relative food value of P. pratensis by an average of 8%, which is sufficient to have nutritional implications for its utilization by herbivores. However, forage quality response to O 3 was not changed by interspecific competition. Lack of injury and nutritive quality response in P. pratensis harvested in September may reflect recovery from early-season O 3 exposure. Early-season O 3 exposure decreased nutritive quality of Poa pratensis, and nutritive quality response to O 3 was not altered by interspecific competition.