Air Pollution Effects on Yield, Quality and Ecology of Range and Forage Grasses

摘要

In order to determine the effects of chronic exposure to ozone and sulfur dioxide on yield and forage quality, seven forage and seven range grasses were exposed to various levels of the pollutants in closed fumigation chambers. Ozone levels were 100, 67, 33, and 0 percent of ambient. Sulfur dioxide was supplied at 10 ppm. Yield parameters studied were total forage dry weight, tiller production and dry weight per tiller. The quality parameters were forage content of nonstructural carbohydrates, crude protein, crude fiber, calcium, magnesium and phosphorus. Chronic ozone exposure affected yield in varying degrees in all of the forage grasses. Effects were also observed on all quality parameters but species differed in their responses. The most pronounced response was in soluble carbohydrate levels. Because species differed in their growth responses to the pollutants, possible changes in species composition of natural grasslands subjected to air pollution must be considered.