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5,000 and Counting
First Extensive Tree Census Concludes

By Carla Garnett

Photos By Damon Tighe

On the Front Page...

Before this past summer, arguably only one man knew every tree on the NIH property. Now, following the campus's first exhaustive tree survey, several more folks have become acquainted with NIH's arboreal residents.


The 3-month, $17,000 tree survey commissioned by NIH's Office of Facilities Planning was conducted by the contractor Davey Tree Experts. Every tree on the NIH property with at least a 6-inch-wide trunk was identified by species and genus, the state of its health evaluated and its location plotted on an aerial map of the campus. They were also tagged with numbered metal plates; the coin-sized plates prompted many NIH'ers to wonder what was going on.

Tree #4454 — located in the center of campus — is in the hospital's backyard.

"This survey was part of our regularly scheduled 5-year updates to NIH's 20-year master plan," said Stella Serras-Fiotes, director of the Office of Research Services' newly constituted facilities planning office. The most recent NIH master plan was completed in 1995, but a comprehensive tree census was not completed at the time. "The results of the survey will serve several purposes," she said. "It will give us the baseline we need for the care and welfare, removal and replacement of our trees. NIH has a self-imposed policy to replace every tree lost due to construction or natural causes with at least one new tree, often more than one. In 1999, 184 trees were lost, but 548 were planted. The survey will give us a document that we can supply to various county planning agencies to support our construction and improvement activities. The survey also tells us which trees are healthy and which may need special care or attention."

One NIH'er who may find the tree census results most fascinating is also the one man who claims to know every tree on campus and who singlehandedly conducted a less high-tech NIH tree survey in the summer of 1980.

NIH's first official tree survey found more than 5,000 mature timbers on campus, and that's not counting the more than 2,500 younger or newly planted trees. Shown above is tree #621, a white pine.

"This tree survey was very economical," explained Lynn Mueller, longtime chief of the Division of Engineering Services' grounds maintenance and landscaping section. A smaller tree census was done around the site for the new Clinical Research Center, in preparation for the construction that began in 1997. Mueller estimates that NIH is home to about 2,500 younger trees in addition to the more than 5,000 mature ones counted in the census. "[The census] only cost us about $3 or $4 per tree and now we know where each tree is exactly located, its species, size and general health. The data base will also provide the history of when and what trees were pruned, fertilized and other facts such as pesticide applications, lightning strikes or other injuries noted. This will be a tremendous help when we need to site new buildings, building additions or extend underground utilities. We can design the structure and utility corridors in ways to miss the mature trees."

NIH takes its tree stewardship very seriously, Mueller said. In the past several years, NIH has concentrated on planting tree species that are native to the area. These include maple, oak, gum and ash varieties, American elm, sourwood, sycamore, hophornbeam and others.

When a tree is lost a replacement is quickly planted nearby, he explained. In fact, a 12-inch pin oak along Center Drive near Rockville Pike, weakened over the years by insects and weather, was removed on Oct. 7. A 10-inch pin oak was transplanted to the exact spot on Oct. 11. This tree was brought in on a 96-inch hydraulic tree spade on the back of a big truck. Last summer, a 217-year-old white oak near Bldg. 61 was hit by lightning and quickly died. Its remnants had to be carefully removed in sections and hauled away. It was replaced with a new variety of American elm that is resistant to Dutch elm disease.

Tree #2128 is an American Sycamore.

Mueller said the next step in the tree project is to replace the nails attaching the aluminum plates to the trees. Because the existing nails and plates will be absorbed by the growing trees in just a few years, he plans to attach 12-inch steel fish leaders (stout fishing line) to the numbered plates. This will allow for years of tree growth before the leader and plates are absorbed.

"We'll probably replace the existing combination over the next 2 or 3 winters," he said.

On demand, Mueller spews facts about the campus's arboreal interests. At over 27 feet in circumference and nearly 10 feet in diameter, the largest campus tree is a silver maple located along Rockville Pike near Cedar Lane, he recalled. The longest surviving and some of the tallest trees on campus are white oaks and tulip poplars in the "Treetops" area near Bldg. 15K. NIH is also listed in the Montgomery County Champion Tree Registry, he pointed out proudly. Last year NIH was recognized by the county's forestry board for nurturing the county's largest known Japanese zelkova tree. The zelkova is not native, however, having been planted in 1972 off the southwest corner of Bldg. 1.

Mueller has already submitted several more nominations to the Montgomery County Forestry Board for consideration of the 2001 Champion Tree designations. "I know every tree on this campus," he concluded, explaining that the census results, which include a 100-plus-page report and a table-size grid map, will probably hold few surprises for him. "But the long term advantage of having a comprehensive census is invaluable."

NIH's Top 10 Timbers

NIH's biggest timber, tree #2315, a silver maple just south of the intersection of Cedar Lane and Rockville Pike, has three low limbs so substantial that they are supported by wooden posts (see above) footed in concrete. The tree gains its extraordinary width because it's really almost three separate trees growing out of a single root (see below).

Below are the top 10 largest campus trees, their tag numbers, trunk sizes in diameter and locations:

1. Silver maple #2315, 118"; Located along Rockville Pike at Cedar Lane

2. White mulberry #2155, 80"; Located south of the Lister Hill Center

3. Corkscrew willow #2153, 75"; Located south of the Lister Hill Center

4. Silver maple #4544, 62"; Located east of the NLM near Rockville Pike

5. Tulip poplar #3230, 61"; Located northwest of 15K near bottom of hill

6. Sycamore #38, 60"; Located east of parking lot 10K

7. Willow oak #4600, 58"; Located between NLM and 32T-2

8. Tulip poplar #3229, 56"; Located just south of #3230

9/10. White oaks #2981 and #3216, 56"; #2981 is located south of 15K on top of retaining wall; #3216 is located north of 15K.

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