Northern Virginia

A photograph in the book shows the ancient oak in all its glory, morning sun streaming through its arching branches, casting shadows on the lawn of a stately house that shields the tree from damaging winds.

"What a tree it is," reads the book on page 22.

"The third largest live oak in Virginia, it has a crown spread of 97 feet and trunk diameter of over 6.5 feet. Like most live oaks, it is not particularly tall (only 57 feet), but its gigantic, flaring trunk and spreading, sinuous branches give it that expressive 'Gone with the Wind' look so typical of live oaks."

The Algernourne Oak is named after Fort Algernourne, which was the first fortification established at Old Point Comfort and the earliest ancestor of Fort Monroe. Built in 1609, it burned in 1611.

Virginia Tech's R.J. Stipes, professor of plant pathology and physiology, estimates the ancient oak germinated in 1540. He bases that date on core samplings he and colleagues took from other live oaks during a study at the fort in 1997, according to the remarkable trees book. The Algernourne was not cored but researchers came up with an average number of tree rings per inch of trunk diameter to establish the tree's age.

As renters begin to occupy the fort's historic brick homes and the public increasingly walks it hallowed grounds, Hugo hopes the fort's trees, including 50 native American elms that survived Dutch Elm Disease, continue to thrive.

"The Fort Monroe property reminds me of the Meadow Farm property that is now the site of the Virginia State Fair," said Hugo.

"Fort Monroe has even more remarkable trees than the State Fair property does, and it probably won't have the same kind of foot traffic that the State Fair property does, but I still worry about soil compaction under those wonderful trees."

Soil compaction around roots can be a problem for any tree, regardless of its age or species.

"Any tree that has lived that long has clearly found favorite conditions, so the last thing you want to do is cause any changes to the site around the tree," said Farrell.

"Older trees are less tolerant of disturbance, particularly to the roots which can spread farther than the crown. The key to prolonging the life of older trees is reducing stress."

Grady Wesson, natural resources manager at Fort Monroe, is in charge of making sure the Algernourne and its kin stay healthy and vigorous. He and his supervisor Robert Reali, Army environmental coordinator, will remain in their caretaking roles after the base closes, they say.

In 2010, Wesson and Davey Tree Expert Co. started a fertilizer program on the trees, injecting nutrients 6 inches deep in 3-inch rings outward to the drip line. During all this, the tree experts discovered the fertilizations help the trees produce enzymes that enable them to better deal with the woolly leaf gall that looks like little tan balls on the undersides of leaves.

In 2009, they gave the Algernourne Oak similar fertilizer injections, in conjunction with a Boy Scout project, and later measured the tree to find it had actually grown some.

"It had 12 inches of growth within six months," said Wesson.