Responses of Agrostis capillaris to gaseous pollutants and wet nitrogen deposition

Aut.: E.A. Kupcinskiene, T.W. Ashenden, S.A. Bell, T.G. Williams, C.P. Edge, C.R. Rafarel. Žurnalo IF - 0,661Bibliogr.: p. 97-99 (43 pavad.)Agrostis capillaris L. plants were exposed to combinations of gaseous pollutants and wet nitrogen mist in Solardome glasshouses. Gaseous pollution treatments were (a) charcoal-filtered air (control), (b) 10 ppb SO2 + 10 ppb NO2, (c) 20 ppb SO2 + 20 ppb NO2, (d) 40 ppb SO2 + 40 ppb NO2. Within each Solardome, four plant blocks were allocated different wet deposition treatments which provided a North Wales maritime rain with the equivalent of 0, 20, 40 or 60 kg N per hectare per year without changes in hydrogen ion concentration. Progressive senescence of leaves in the gaseous pollution treatments correlated well with leaf dry weight data, showing increasing injury with time. Growth analysis was performed after 11, 13 and 15 weeks exposure to pollutants. Gaseous pollution treatments resulted in substantial reductions in leaf areas and dry weights of A. capillaris in both the 20 ppb SO2 + 20 ppb NO2 and the 40 ppb SO2 + 40 ppb SO2 + 40 ppb NO2 treatments compared with the plants exposed to charcoal filtered air and the 10 ppb SO2 + 10 ppb NO2 treatment. Adverse effects of the gaseous pollution treatments were greater on shoots than roots. Additions of wet nitrogen caused reductions in the numbers of tillers and leaf areas of A. capillaris compared with plants with zero nitrogen application. There were no effects of wet nitrogen treatments on total plant dry weights but all nitrogen additions above zero application resulted in a reduction in root dry weights at the final harvest which was reflected in a decrease in root/shoot ratio in the 60 N treatmentVytauto Didžiojo universitetasŽemės ūkio akademij