Betula alleghaniensis to the thin bark and lack of ability to resprout, it is easily killed by wildfire. Sugar maple ("Acer saccharum") exerts allelopathic effects on seedlings of yellow birch and decreases their growth ability. The inhibitory chemical is exuded from the roots of the sugar maple and has a very short soil half-life, it no longer has effects on birch after 5 days. It is listed as endangered in Illinois. Yellow birch is considered the most important species of birch for lumber and an important hardwood timber tree; as such, the wood of "Betula alleghaniensis" is extensively used for flooring, furniture,
Alnus cordata with a very long season in leaf, from April to December in the Northern Hemisphere; they are alternate, cordate (heart-shaped), rich glossy green, 5–12 cm long, with a finely serrated margin. The slender cylindrical male catkins are pendulous, reddish and up to 10 cm long; pollination is in early spring, before the leaves emerge. The female catkins are ovoid, when mature in autumn 2–3 cm long and 1.5–2 cm broad, dark green to brown, hard, woody, and superficially similar to some conifer cones. The small winged seeds disperse through the winter, leaving the old woody, blackish 'cones' on the tree