Tuesday, November 3, 2009

A Mast Bonanza

Acorns are abundant across central Missouri this year. Well beyond the capacity of natural consumers to eat or store them, the nuts and their fragments coat lawns, roads and walkways.

These nuts are, of course, the fruit of oak trees; more than 600 species of oak can be found across the globe and more than 60 are native to North America. Most oaks are deciduous trees but some, including the live oak of the southeastern U.S., are evergreens; acorn production begins as early as 10 years and as late as 50 years after germination, depending on the species. The white oak family (which also includes bur, gambel, post, chinkapin and chestnut oaks, among others) produce acorns that mature within 1 year and do not have a bitter taste. The red oaks (including scarlet, pin, black, live and willow oaks, among others) produce acorns that mature in 2 years and, due to the presence of tannins, have a bitter taste.

Oaks produce acorns every year but, in mast seasons, which occur every 2-7 years, a dramatic abundance of the nuts are shed; these peak crops result from both innate, natural cycles of the various oak species and seasonal weather variation. This year's mast bonanza will also boost populations of acorn consumers (squirrels, chipmunks, jays, woodpeckers, bears, deer, turkeys, skunks and others) by favoring their winter survival. Native Americans also counted on the mast of autumn and, after leaching tannins from the acorns, would store them for use throughout the colder months.