Height Growth and Tissue Sulfur Content of Field-Grown Tree Seedlings from Different Sulfur Dioxide Environments

A comparison of height growth and tissue sulfur content was made for two-yr-old containerized seedlings of sugar maple (Acer saccharum Marsh.), flowering crabapple (Malus coronaria (L) Mill.), flowering dogwood (Cornus florida L.), Fraser fir (Abies fraseri (Pursh) Poir.) and white pine (Pinus strobus L.) growing in the field under different ambient sulfur dioxide (SO₂) conditions. Total height and rate of height growth for crabapple, sugar maple and white pine were significantly less in the high-ambient SO₂ environment compared to similar plants at the low-ambient SO₂ location. Two patterns of growth were observed for seedlings at the high-ambient SO₂ site. One was a delay in the period of maximum growth (crabapple and dogwood); the other a flush of growth late in the season (sugar maple, white pine and Fraser fir). The sulfur content of plants from the high-ambient SO₂ site suggests that all species tested were capable of filtering some SO₂ from the atmosphere, with the foliage being the most effective sorptive tissue.