Saturday, November 3, 2012

The mighty white oak

Species name: Quercus alba (hybridized with...?)

Common name: white oak

Location: Ontario

I took this photograph of a white oak on campus, and I doubt it's a "pure" white oak. The swamp oak (which you can read about HERE) and the white oak are not only very closely related species, but they also readily hybridize. For anyone to sell a "pure" white oak, I would like to know how they did it. Collecting acorns in the wild and growing up trees in a nursery (then repeatedly harvesting nursery acorns and replanting to grow up your stock) will almost always result in hybridized white oaks. And if the tree nursery also grows swamp white oaks, they've compounded their problem. In fact, oak pollen is so light and can travel so far on wind currents that you don't even have to know where a swamp oak or a white oak are to get them to hybridize. Like the issue with the Freeman maple (which you can read about HERE), once these two species hybridize they often get intermediate features, or a "blending phenotype." Oak pollen is actually one of the leading causes of seasonal allergies in the spring. Anyone living near an oak tree can attest to this; my dark grey car often takes on a yellow tinge because of our big red oak growing in the front yard.

The white oak, no matter its genetic background, has been used for centuries as one of the most prized woods in the world. Because of the structure of the cells in the wood, it is completely watertight when used for making furniture or other items. These same cellular structures make it rot-resistant, which is why it is so popular in the use of barrel construction; the liquid won't leak out of the barrel, and if it does start to become saturated with the liquid inside it won't rot and release the contents. Not cracking and breaking apart is probably preferred during the alcohol aging process! It's not just wine that's stored in oak barrels, but also rum and whiskey. Since some rums are aged for 20 years or more (an Appleton Estates rum to be released this year is a 75 year aged rum, all done in oak barrels), putting them in a barrel that's likely to rot or leak is probably not preferred! The watertight and rot-resistant characteristics also make oak a popular wood historically for shipbuilding and agricultural construction (both equipment and barns).

On the inside of homes, oak is a popular wood for visible finishings. Sometimes cabinets are made out of a different kind of (cheaper) wood, then the front facings are oak. Oak flooring is also incredibly popular, and often it's even stained to resemble other, more expensive woods (like cherry, walnut or mahogany). In fact, most mahogany flooring sold today in Canada is just white oak wood stained a reddish colour, since international trade treaties have been signed preventing the import of South American tropically-grown mahogany wood into Canada. Since the term "mahogany" doesn't actually apply to any one species of tree (unlike wood from black walnut, white oak, sugar maple, white pine, etc.), that eliminates many options for sourcing mahogany! While I'm sure mahogany is incredibly popular to use for fine furniture and household finishings, South American rain forests are being eliminated at an alarming rate for both the international wood trade, and conversion to the North American style of farming (higher productivity for a few years, but then a drastic decline in productivity due to the low level of nutrients in the soil). By preventing the import of these trees, we are doing our part in attempting to conserve the tropical forests in South America.

There are some notable famous white oaks across the United States. The first isn't one tree, but actually an entire grove of white oak trees. The USS Constitution is made entirely of white oak, and whenever parts of it need to be replaced they come from a grove of trees called Constitution Grove near Bloomington, Indiana. The states of Connecticut, Maryland and Illinois have all made the white oak their state trees, with one specific oak representing the honorary tree of the state. The Charter Oak in Connecticut is even featured on the back of their state quarter (which I, of course, proudly own since it features a botanical design). The honorary state tree of Maryland, the Wye Oak, was one of the oldest living trees in the United States until it was destroyed in a storm in 2002. In Illinois, they couldn't decide which tree they liked better to serve as their honorary white oak so they picked two; the first is on the front lawn of the governor's house, and the second is in a school yard. The new largest living white oak is the Linden Oak, also located in Maryland.