Last summer was harder than most for trees and their human supporters. The spring’s nonstop rains inundated soils and caused root systems of many large, old trees to partially decay. Then, when the summer’s drought hit, trees could not tap deep sources of water that would normally have sustained them. Many cherished old trees died, especially oaks.
I volunteer on the Mount Rainier Tree Commission. We heard from many residents who were concerned about their trees. We had little to offer them. That’s because public and private urban tree resources and programs are geared almost entirely to planting trees and almost not at all to maintaining trees. No state or county program that I could find provided any financial resources for maintaining tree health. Private residents and small, under-resourced cities such as ours were on their own.
This is backward. Scientists are learning that large, old trees are the most valuable, especially in cities. They capture the most storm water and take the most pressure off our overtaxed streams and rivers. They put on wood fastest and take the most carbon out of the air. They harbor the most wildlife. They can lower summer temperatures by 20 degrees or more. They raise property values.
In a recent study, researchers found that Boston would get more benefit from keeping the trees it has alive than from planting new trees. There’s reason to think this finding would apply in other cities, too.
That’s what’s quantifiable. Then there’s what’s not. Just compare your emotional response when looking at a twiggy sapling to that when encountering a grizzled old giant, whose bark shows signs of battles fought and won against insects and weather, whose massive limbs branch in wild, unpredictable ways, whose very existence speaks to some of our most valued characteristics: resilience, regalness, care for other life. Trees, like us, gain character and personality as they age. Every old person’s face is wrinkled and weathered in its own particular way.
Our public and private tree programs reflect little recognition of the value of big, old trees. Governments and nonprofits are practically handing homeowners and property owners money to plant trees. In the District, Casey Trees plants thousands of trees per year. Thousands of Chesapeake Bay-related dollars go toward new trees. Yet anyone wanting to sustain older trees may need to shell out a thousand dollars or more annually for arborist visits, pruning of dead and decaying limbs and treatments to prevent fungal and insect attacks. So aging trees are often neglected until it’s too late.
Regulations and enforcement also are important; development, driveway construction and paving need to be tailored to avoid harming old trees’ root systems, which can tunnel as far underground as the canopy extends above ground. In our region, the District and Takoma Park have strong tree ordinances, but many jurisdictions lag.
As long as we abandon our old trees, we will be like hamsters on a wheel, planting furiously merely to keep pace with mounting losses. Shade-giving tree canopy will not expand. Polluted storm water sloughed off roads, buildings and parking lots will continue to wash into streams, rivers and the bay. We want trees to help protect us from the hotter weather and more intense storms that climate change will bring, yet by failing to care for trees, we leave them vulnerable.
I get it: It’s easy to get donors or taxpayers excited about organizing 100 volunteers to plant 1,000 trees. Nobody gets excited about the words “preventive maintenance.”
Consider another analogy to the human world: Nobody would send a baby into the world and expect it to just make it. Children need nurturing; it’s why we fund schools and child health-insurance programs (though not to the extent that we should). Trees are the same. We could get so much more out of our trees if we just put a little more into them.