Forest decline by immission stress - a problem concerning only the tree layer? : Air Pollution and Forest Decline. 14th International Meeting for Specialists in Air Pollution Effects on Forest Ecosystems

1989

1 Abb., 5 Tab., 32 Lit. Ang., En, Zfsg. En

Unselbständiges Werk

9091

200034685

Research on air pollution effects on forest ecosystems focusss on the tree layer. However, changes in species compositon of the herb layer of forests have been reported in several descriptive studies. Experimental data on the sensitivity of native forst understory plants are lackin. In this study, the native harv layer of a beech forest was fumigated with moderate doses of SO2, NO3 and O3 in open-top chambers. The fimigant efect was dependent on species. Allium ursinum L. reacted very sensitive. This species experienced an early senescence after fumigarion, and its generative reproduction was rediced. The treatments injured the epicuticular waxes and led to leaching of nitrents. Gas exchange measurements revealed stomatal closure and diminished carbon dioxide assimilation during the funigations. The fumigant doses, averaged than at the control plots. The consequences of gaseous air pollution to native forest floor plant communitites are discussed.