The Big Trees of Patuxent

Matthew C. Perry
Patuxent Wildlife Research Center

The trees stand tall at Patuxent - and indeed they should. Protected for over 60 years and growing in one of the most fertile floodplains of North America, they've done okay for themselves. Because there has been no recent lumbering, the forest at Patuxent is predominated by specimens at least 60 years old. In the floodplain area, however, some trees are approximately 130 years old. Their age is known because 60 years ago when the Government constructed a road through the floodplain many of the cut trees were aged at 70 years old, based on counting annual growth rings.

Some areas of Patuxent have small stands of trees which are probably over 200 years old, because these areas were never cut. They exist in remote areas on small islands within the multi- branched Patuxent River. These so-called " virgin forests" contain some of the largest trees - the grandaddies of the forest.

The largest tree ever measured at Patuxent was on one of these islands (Beech Island). It was a yellow poplar (tulip-tree) with a trunk circumference of over 18 feet and a diameter of almost 6 feet. Unfortunately, this mammoth tree died in 1986, and only its rotten trunk remains. But don't despair for within a stone's throw is another yellow poplar only a few inches less in circumference and diameter. Folks, we're talking big!

Beech Island, as you might expect also has some large beech trees. The second largest beech tree (diameter 52") in the state stands proudly on the upstream end of the island, and has provided support for a red-shouldered hawk's nest for many years. The state's largest pignut hickory (diameter 33") and a sweetgum with a 46" diameter are also on the island.

Over the years Patuxent has claimed some U.S. record size trees based on official measurement rules of foresters. Botanist Neil Hotchkiss and his colleagues conducted the first big tree survey in the 1950s. An overcup oak with a 5-foot diameter was the largest for its species for the whole United States. Unfortunately, this tree fell over in 1972 and now slowly rots on the forest floor. Several large overcups are within a short distance of the old champion and one is 4 feet 7 inches in diameter and presently listed as the second largest in Maryland. In 1999, the largest overcup oak tree in Maryland died and so now Patuxent has the largest for the state, and who knows maybe someday it will be the largest in the United States.

Another U.S. record was a river birch which measured almost 4 feet in diameter. This tree has not been found in recent years and probably has died and already returned to the forest soil. Foresters are presently looking for new record trees of these two species in the same areas where the U.S. champions were.

At present Patuxent can boast several State record trees and many Prince George's County record trees in upland sites. A pitch pine with a diameter of 2 feet 6 inches is the largest in Maryland. The northern catalpa at the Endangered Species Research Area near the Crane Chick Building is the third largest for the state and raises eyebrows with its 13-foot circumference and 4-foot diameter. One of Patuxent's red cedar trees is the second largest in the State with an 11.5-foot circumference and 3.5-foot diameter. A sweet cherry (diameter 34") is the second largest in Maryland. Two trees growing not far from the historic Snowden Hall and both state records are a sweetbay magnolia (diameter 8") and an exotic Japanese pagoda tree (diameter 35").

Official measurements have not been conducted on many of these trees, however, so there could be some interesting surprises. Many of Patuxent's big trees occur in the dense forest and therefore don't reach the diameter or canopy of those found growing in the open where they get more sun and less competition from other trees. To account for this bias from growing conditions, foresters use three measurements (diameter, height, and canopy cover) to score the big trees. By using this scoring system, a numerical value can be obtained that clearly shows what is the largest tree, but not necessarily the oldest.

Other trees at Patuxent that are of interest to foresters and naturalists include a sycamore (6 feet in diameter) growing in a damp site not far from the Little Patuxent River and a multi- trunked redbud which is 44" in diameter at the base but only 13" in diameter for the largest trunk at breast height. A sycamore maple, which is only 12" in diameter, is unique because it is the only known one of its species in the county. A swamp white oak (3.5 feet in diameter), a swamp chestnut oak (4 feet in diameter), and a willow oak (5 feet in diameter), are all the survivors of disease, lightning, fire, flood, and drought. They have endured where other trees failed. They deserve our respect for surviving, but they also warrant our thanks for providing cleaner air and a more interesting environment for all humans to enjoy.

[Big Tree Table]

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