The volume of soft maple has increased significantly since 1983. Soft maple, like many. other species groups, is aging. The volume in large trees has more than tripled in the. last two decades. Along with volume, the rates of growth and mortality have also increased. But the ratio. of mortality to volume for soft maple is much lower than the average for all species. Whereas soft maple makes up about 11.3% of volume and 13% of growth of trees in. Wisconsin, it accounts for only 4 % of total mortality. Soft maple is an important timber species, making up 7.4% of roundwood production.