Effects of Controlled SO2 Exposure on Net Primary Production and Plant Biomass Dynamics

Abstract

Objectives of this study were to determine effects of low level SO2 fumigation on above- and belowground plant biomass dynamics and aboveground net primary production. With two exceptions we were unable to measure significant effects on these parameters. Rates of increase in rhizome biomass over the 4-year period of the study were reduced by SO2 and indicate that longterm exposure of this grassland to low level SO2 may ultimately reduce the vigor of the perennating organs to a point where above- and belowground biomass dynamics will be altered, net primary production will be reduced, and species composition will be modified. In addition, production of Bromus japonicus, a cool-season annual grass, was reduced by SO2 fumigation.