Memphis has one of the finest urban forests in the nation, but old age and two summers of drought combined with mismanagement are bringing down some of our biggest trees, say local tree experts.
Though a tree ordinance passed last fall provides limited protection against clear-cutting development sites, Memphis still needs a full-time professional to manage its urban forest and a system to protect the city's significant individual trees, says Don Richardson, who developed a "heritage tree" program cut from the final tree ordinance.
Trees are oxygen-generators and can save up to 30 percent on cooling costs through shade, provide habitat for animals, and beautify cityscapes, Richardson says. That's why many cities assume the cost and responsibility of caring for their oldest and biggest trees.
"So many times a neighborhood is defined by its big trees," Richardson says. "Big trees are natural historic structures and deserve to be protected and celebrated for all they provide to the community."
It's a classic Midtown tree situation, says Fred Morgan as he looks up at a 75-year-old willow oak. Green and seemingly healthy, the 70-foot-tall tree shades a schoolyard and a nearby house. A yellow shelf-like fungus along its lower trunk could indicate disease, and the owner wants to make sure the tree is stable.
Using 26 years of experience and high-tech equipment, Morgan determines if the tree is healthy or needs to be cut back or, in a worst case scenario, taken down.
Morgan is a certified arborist, but since Tennessee doesn't offer arborist certification, training isn't required for tree-care professionals.
"We're behind the nation in requirements for arborists, even though more and more people are beginning to understand the concept of what a certified arborist is," Morgan says. "Right now all you need is a business license, rope, pickup truck, and chainsaw and you can be in the tree business."
Because falling branches can be a hazard and preventative care can save a tree, homeowners should be aware of their trees' health. Dying branches in the canopy, fungus along the base of the trunk, and small shoots off the main branches are obvious signs the tree could be diseased and need professional attention.
Morgan recommends choosing a certified arborist to diagnose tree problems, because many tree workers only know how to take a tree down or recommend "topping," which removes the uppermost branches. Topping forces the tree to grow "waterspouts" -- fast-growing leafy shoots off main branches. These are a tree's emergency response to losing leaves, where food is made through photosynthesis.
Unfortunately, Morgan says, most people think in years rather than decades when planting a tree. This leads them to choose the wrong kind of tree or to plant a tree in a place where it doesn't have enough room to grow.
Loblolly pines, Bradford pears, and willows are often chosen for their fast-growing canopy, he says. But wood that grows fast doesn't grow strong and fast-growing trees have a shorter life span.
Most trees, especially oaks, like to spread their roots at least as wide as their limbs, Morgan says. And if the tree doesn't have sufficient room to grow, it is less healthy and in extreme cases could topple over in the direction its roots are restricted.
Other common mistakes are planting trees too deep, planting in the heat of the summer, disturbing a shallow root system, and using bad watering techniques. Morgan says trees need three or four hours of watering every five or six days rather than a shorter daily treatment.
"In our fine clay soil, watering too frequently and shallowly can cause the upper soil to compress, forming a cap that can prevent aeration and root function," Morgan says.
Trees have a definite lifespan, and Memphis' urban forest has certainly entered old age, he says. Age and the droughts of the last two summers have made the city's trees more susceptible to disease and decay.
Most cities employ an urban forester to take care of the trees, but Memphis relies on a handful of trained arborists, some poorly trained "professionals," and homeowners with hacksaws, Morgan says.
The Division of Forestry under the Tennessee Department of Agriculture has a position for a regional forester in Shelby County, but because of a state hiring freeze no one can be hired, says Kay Ferman, who works as an urban forester for the department in eastern Tennessee.
The department provides technical assistance and education and distributes $200,000 in federal grants for tree plantings and maintenance. The city of Lakeland and the Memphis Division of Park Services have received grants to hire arborists to maintain their part of the urban forest. Morgan works as a subcontractor for Park Services, inspecting and working on the trees in Memphis parks. This spring, many diseased, dying, and unsafe trees were removed along the parkways, and 300 trees were planted to fill in the gaps.
"Park Services knows the urban forest is one of Memphis' major assets," says Cary Holladay, public affairs manager for the Division of Park Services. "It's important to realize the forest has a definite lifespan that requires maintenance and management, and sometimes it is necessary to replace some trees."
Most of the trees planted were a variety of oak or other species native to this region. Park Services will soon begin advertising for an urban forester, but Holladay says the position will only cover trees on parkland -- leaving the remainder of the city's urban forest unmanaged.
As traffic rushes by on North Parkway, centuries-old hardwoods are reaching the end of their life while stick-like saplings reach skyward. Thanks to city services, here along the parkways, at least, the urban forest's cycle of life is continuing, providing an example of how to maintain our canopy of green for generations to come.
You can e-mail Andrew Wilkins at firstname.lastname@example.org.