Quercus Macrocarpa - Ecology

Ecology

Bur Oak typically grows in the open, away from forest canopy. For this reason, it is an important tree on the eastern prairies, often found near waterways in more forested areas, where there is a break in the canopy. It is also a fire-resistant tree, and possesses significant drought resistance by virtue of a long taproot. New trees, after two to three years of growth, may have a 1–2 m deep taproot. The West Virginia state champion Bur Oak has a trunk diameter of almost 3 m (9 feet).

The acorns are the largest of any North American oak (thus the Latin species name macrocarpa--large fruit), and are an important wildlife food; American Black Bears sometimes tear off branches to get them. However, heavy nut crops are borne only every few years. In this evolutionary strategy, known as masting, the large seed crop every few years overwhelms the ability of seed predators to eat the acorns, thus ensuring the survival of some seeds. Other wildlife, such as deer and porcupine, eat the leaves, twigs and bark. Cattle are heavy browsers in some areas. The bur oak is the only known foodplant of Bucculatrix recognita caterpillars.