Wednesday, October 19, 2016

Witnesses to History: The Trees of Duke Gardens

By Sarah Leach Smith, Visitor Services Coordinator
Photos by Jason Holmes, Doris Duke Center Gardens Curator

Trees stand as silent sentinels, witnessing celebrations and disasters throughout history. Imagine what the trees of Duke Gardens could tell you about the Civil War in this country, the first human on the moon or the musical sounds of the Big Bands in the 1940s. The trees at Duke Gardens have also heard the echoes of many great speeches over the past centuries, from Abraham Lincoln’s Gettysburg Address to Franklin D. Roosevelt’s first inaugural address in 1933.

Here at Duke Gardens, we invite you to treasure these witness trees and learn their stories.

Iconic southern magnolia in the Historic Gardens.
One of the most iconic southern trees is the southern magnolia (Magnolia grandiflora), and Duke Gardens is often remembered for the many southern magnolias growing in the Historic Gardens. These trees began their life at the Gardens as saplings, planted in 1938. Their huge, fragrant, creamy white flowers, thick evergreen leaves and sturdy low branches invite visitors to enjoy the trees’ embrace.

Our southern magnolias grew tall and strong while World War II was raging in Europe, and the university placed a priority on studies in engineering, chemistry research and medical advancements so that we could do our part in the war effort.

Another significant species in our collection is dawn redwood (Metasequoia gylptostroboides), which can be found between the Historic Terraces and Fisher Amphitheater. It is an unusual tree, because the leaves are needles but are not evergreen. The needles of a dawn redwood drop in autumn just like maple and oak leaves do.

This dawn redwood has had quite a life.
Fossils show that dawn redwood was a dominant tree in much of the Northern Hemisphere about 90 million to 150 million years ago. That means that dawn redwood species were around during the time of the dinosaurs and have also seen the evolution of humans. These trees were largely believed to be extinct until a few living trees were surprisingly discovered in a remote part of western China in 1941. Seeds collected from that Chinese population were germinated at the Arnold Arboretum of Harvard University in 1948.

The following year, one of those original seedlings was planted here at Duke Gardens. That dawn redwood still stands, marked with a plaque and surrounded by a chain stanchion for protection. In its lifetime, Neil Armstrong was the first human to walk on the moon and Duke University was desegregated. We have since planted additional dawn redwoods to ensure that there will always be a healthy specimen in our tree collection.

Gorgeous fall color of the maidenhair tree.
Near our dawn redwood is a large maidenhair tree (Ginkgo biloba).  Like dawn redwood, it is considered a living fossil. Fossil records for the maidenhair tree date back to more than 200 million years ago! Our large specimen was planted approximately 50 years ago, and it puts on an amazing color show each fall as the leaves turn golden yellow and rain down on the grass below. Since its installation, Martin Luther King Jr. gave his momentous “I Have a Dream” speech and Johnny Carson hosted his final episode of “The Tonight Show Starring Johnny Carson.”

Though it’s called the Historic Gardens, this area of Duke Gardens is not the only place you will find historic trees. Venture over to the Culberson Asiatic Arboretum to see more notable specimens.

Entering the arboretum from the Mary Duke Biddle Rose Garden, you will see a substantial American sycamore (Platanus occidentalis). Sycamores are easily identifiable by their large tent-like leaves and by their exfoliating bark, which peels back to reveal a white and light gray mottled smooth inner bark. This specimen was likely planted here by a person, as sycamores typically grow in fine-grained organic soil made up of river deposits, and Duke Gardens has a different soil type.

This sycamore is at least 75 years old and has been through a lot since being planted here—you can see an interesting cavity coming down the trunk from a past injury. While we’re not sure what caused the cavity, theories include a lightning strike or a large branch that ripped off the trunk. During its lifetime in the Gardens, this tree witnessed the only Rose Bowl football game played outside the state of California—it was hosted by Duke and held at Wallace Wade Stadium in 1942.

On the north side of the arboretum, you’ll find one of the tallest trees in the Gardens—a southern red oak (Quercus falcata). Estimated at between 175 and 200 years old, this tree was just starting as a small acorn when James Monroe, the fifth president of the United States, was in office. These days it is still very healthy and, like most old oaks, will occasionally drop old limbs onto the ground below.
One of the towering loblolly pines in the Blomquist.

The Blomquist Garden of Native Plants has its own historic witness trees, including loblolly pines (Pinus taeda). There are two large specimens by the main entrance to the Blomquist and another at the Blomquist Pavilion. These pines are around 150 to 160 years old, which means they were alive at the same time as the Civil War.

Loblolly pines, including the ones in the Gardens, are an interesting example of the effects that humans have had on the environment. Though loblolly pines seem ubiquitous these days, this was not always the case; longleaf pines (Pinus palustris) dominated the piedmont landscape for hundreds of years. Some plants, including longleaf pine, need fire to help their seeds spread and germinate. Other plants, like the loblolly pine, are greatly harmed by fire, causing populations to be suppressed. As humans inhabited more of the landscape, they also worked to minimize fires. This resulted in a decrease in fire-dependent longleaf pines and an increase in loblolly pines. That is why there are now so many loblolly pines in the piedmont.

Loblolly pine seeds were carried aboard the Apollo 14 flight as part of a joint project with NASA and the U.S. Forest Service. After the shuttle’s return, the seeds were germinated by the U.S. Forest Service and planted in several locations in the U.S., including the grounds of the White House. As of 2016, a number of these “moon trees” remain alive today and stand as a tribute to the Apollo program.

All of the trees in our collection have witnessed some incredible moments in their lifetimes, and with proper care and respect from our staff and visitors alike, they will witness many more. We continue to add to our collection, planting trees that will witness great moments to come.

For more information about out tree health, check out some of our upcoming classes, including “Pruning Young Trees for Structure and Health” and “Caring for Your Landscape.”

Paul Jones, curator of the Culberson Asiatic Arboretum, contributed to this report, along with Blomquist Garden of Native Plants curator Stefan Bloodworth, plant collections manager Beth Hall, and Jan Little, director of education and public programs.

No comments:

Post a Comment