Impact of Ozone On the Growth and Reproduction of Understorey Plants in the Aspen Zone of Western U.S.A.
1975; Cambridge University Press; Volume: 2; Issue: 1 Linguagem: Inglês
10.1017/s0376892900000564
ISSN1469-4387
AutoresM.R. Harward, Michael Treshow,
Tópico(s)Botany and Plant Ecology Studies
ResumoThe purpose of this study was to learn how ozone might affect the growth and reproduction of understorey species of the aspen community, and thereby influence its stability and composition. Plants of 14 species belonging to the aspen community were grown in greenhouse chambers and fumigated with ozone for 3 hours each day, 5 day per week, throughout their growing-seasons. The plants were exposed to 30 pphm (parts of ozone per hundred million parts of air), 15 pphm, ambient air reaching 5–7 pphm during about 2 hours each day, and filtered air. Exposure to ambient air did not appear to cause a significant reduction of total plant-weight in any of the species investigated, while plant-weight of Achillea millefolium and Isatis tinctoria grown under such conditions was significantly greater than that of control plants grown in filtered air. At 15 pphm, growth of Isatis tinctoria, Madia glomerata , and Viola italica , was significantly reduced; on the other hand, growth of Ligusticum porteri and Polygonum aviculare was increased. At 30 pphm, growth was substantially suppressed in all plants except Chenopodium album and Phacelia heterophylla .
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