Morton Arboretum exhibit highlights endangered trees

When you think about endangered trees, perhaps your mind travels to South American rain forests where slash-and-burn harvests have drastically damaged the landscape.

Maybe you've seen pictures of hungry koala bears whose eucalyptus diet has been challenged by habitat destruction.

These images are compelling, yet far away.

Or are they?

“No tree and no country is safe,” says Leslie Goddard, exhibit developer at the Morton Arboretum in Lisle.

Goddard helped design the arboretum's newest exhibit, “Vanishing Acts: Trees Under Threat,” which explores the very real possibility of extinction for more than 8,000 tree species — about 10 percent of the world's total species.

Despite its cautionary tale, visiting the exhibit can be uplifting. Set among the arboretum's conifer collection, interpretive displays explain which trees are threatened and what can be done.

The quarter-mile mulched trail winds through groupings of beautiful pines, spruces, and other evergreens creating a “gallery effect” of intimate spaces, according to Goddard.

“We didn't want to downplay the crisis,” she says. “But we wanted to talk about the many benefits of the trees, and find ways people can connect with them.”

The brazilwood tree, or Pau brasil, is one that anyone who loves music would appreciate. Pau brasil is the main wood used in bows for stringed-instruments.

Imagine Yo-Yo Ma without his cello, or the Hallelujah Chorus without violins. Brazilwood has been exploited for centuries, beginning in the Renaissance era when it was used to make red dye, and continuing through more recent overharvesting.

Or, how about the Pacific yew tree? This Pacific Northwest native evergreen once was considered a trash tree, and was wantonly cut down in logging operations for more valuable timber. In the late 1960s, researchers discovered that chemicals in the Pacific yew bark were very effective in treating cancer. By the 1980s, chemotherapy using Pacific yew-derived medicine was popularly used in fighting cancers of the breast, ovaries and lung, among others.

The demand for the drug exploded, yet supply was scarce since the tree is slow-growing and great quantities of bark are needed to produce a small amount of the drug. In 1992, Congress passed the Pacific Yew Act to promote sustainable harvests on federal land, but the damage had been done.

In 1998, the Pacific yew landed on the “Red List of Threatened Species” monitored by the International Union for Conservation of Nature.

Arboretum staff chose to highlight 15 threatened species of the 8,000-plus that are endangered worldwide. The 15 represent different countries of origin and differences in the severity and cause of the threat.

“There are many misconceptions about endangered trees,” Goddard says.

Many people think global warming accounts for all threats to trees, however medical exploitation, overlogging, pests and other factors contribute. Awareness surveys conducted by the arboretum in developing the exhibit showed many people were concerned about threats to the American elm and ash trees, but these species, while plagued by insects, are not actually on the endangered list.

Who would imagine, for example, that an apple tree is on the threatened list? Malus sieversii, the wild apple native to the mountains of Central Asia, is endangered by loss of habitat. Unrestrained development has forced more grazing in the mountainous areas where the wild apple grows.

Recent DNA analysis has shown that this apple is the ancestor of virtually all apples we eat today. Scientists believe it may have genetic material that could help develop apples with greater resistance to disease and climate change.

So, what can we do to make sure future generations can have an apple or more a day, improved cancer treatments, and violin music? Goddard notes that the “Vanishing Acts” exhibit offers suggestions for all threatened species ranging from consumer awareness to proactive planting of trees.

There is hope, after all. The bristlecone pine is on the IUCN Red List, threatened by a destructive pathogen. Yet, high in the White Mountains of eastern California, thrives Methuselah, a bristlecone pine and the oldest known living tree in the world.

Named after the biblical ancient man, Methuselah's age is estimated at nearly 5,000 years. Protected by a national forest, its exact location is undisclosed to prevent vandalism.

Bristlecone pines have much to tell us about survival and resilience.

The arboretum exhibit includes live specimens of five of the 15 threatened species. Eighteen individual trees are tagged so you can appreciate their beauty and unique characteristics.

The exhibit runs through September, and winter, with snow dusting the conifer “galleries,” is a great time to catch the “Vanishing Acts.”

Ÿ Cathy Jean Maloney is a writer for the Morton Arboretum. Visit the arboretum's website at www.mortonarb.org for details on the Vanishing Act exhibit and other events.

If you go

What: “Vanishing Acts: Trees Under Threat”

Where: Morton Arboretum, 4100 Route 53, Lisle

When: Runs through September 2012

Cost: $11 for adults, $10 for seniors and $8 for children; prices increase $1 per category on Jan. 1

Info: (630) 968-0074 or mortonarb.org