By Sarene Marshall, The Nature Conservancy
Given my work for a global conservation organization and my residence in a neighborhood filled with massive oaks, maples and hickories, it shouldn’t be surprising that my family and I are fond of trees.
And while we should all welcome any shade we get during another summer of record-breaking heat, even the most conservation-minded amongst us might find our love for trees tested right about now. You may not even feel like hugging one. After all, severe storms, like the derecho that freight-trained through the DC area recently, brought branches and trunks down on power lines and property and left millions without electricity for days. Meanwhile, epic large-scale forest fires, like the recent devastating blaze in Colorado Springs, have burned through much of the western U.S., threatening homes and businesses in their wake.
No, this hasn’t been a good PR month for trees.
I heard that one neighborhood proposed the drastic measure of cutting all their trees down. With global temperatures soaring, in part because of carbon pollution caused by massive deforestation in the tropics, that seems a little like cutting off your nose to spite your face.
Yet, after days of being trapped in a 100-degree house with no air conditioning and seeing the horrifying images of scorched earth and destroyed neighborhoods, I sympathize with the instinct to prevent future disasters by getting rid of a perceived cause.
But, when it comes to managing the roles that trees play in these disasters, there is a better way. The secret lies in observing forests over time in the wild.
If you walk through the dense canopies of the Amazon or Borneo, or even the Appalachians and other forests in the US, you notice that nature has a way of “self-managing” to reduce the kinds of risks we face in highly converted neighborhoods in the United States.
In natural forests, trees grow together to form ecosystems that are self-supporting. Closely-spaced trees protect one another from wind. Old and sick trees are often overtaken by vines and insects; they eventually fall and/or die, and decompose. Younger trees in the understory take advantage of the canopy opening to access more sunlight and fill in the gaps. The diversity of shapes, sizes, and ages in the forest makes for fabulous habit for all kinds of other flora and fauna.
When left to their natural devices, drier forests, like those found out west, have historically experienced ground fires that would clear underbrush and thin out smaller trees, reducing the chance of dangerously hot blazes. Without these occasional burns, dense trees and thick underbrush serve as potent fuel for the massive burns we’re seeing this summer.
As I look out at my own backyard, I see where things have gone wrong. A well-meaning former owner planted “low maintenance” English Ivy. The invasive non-native plant, left untended, raced up several trees, creating wounds in their trunks into which marched colonies of termites and carpenter ants. As these trees died, their neighboring trees were robbed of the safety in numbers against wind and heavy rains, and the standing dead or wounded trees became liabilities when storms come through. Just last year, Hurricane Irene downed a termite-eaten hickory that nearly took out our shed.
Making matters worse, these decades-old icons of our neighborhood aren’t being replaced with new growth, due at least in part to gardeners routinely cleaning up “weeds” (which many people define as anything that grows where we don’t want it), thereby preventing young saplings from getting a strong foothold.
In the West, development interventions have caused even more dramatic problems. Last century’s policy of extinguishing all natural fires in American forests—for fear they would threaten people and property—has left us with a tinderbox of choking brush and densely packed trees that, in the face of a warming planet, takes little to ignite.
Unfortunately, we can no longer simply let nature do its thing. We’ve altered the landscape so much over time that the trees need a little help.
In the West, our forests need more frequent, low-intensity controlled burns performed by fire experts to mimic the natural cycle. This will help keep the “kindling” on the forest floor in check, reducing the risk of explosive megafires.
And in my town, it means clearing out unhealthy trees and planting some new ones, so our beloved shady neighborhood can persist for the next generation.
To re-create a bit of the natural processes for healthy trees where you live, consider:
- Removing dead wood/trees before they become storm hazards
- Clearing underbrush to discourage pests and reduce fire risk
- Keeping invasive species, like English ivy, in check
- Planting new trees in your backyard, especially as older ones die off, and/or participating in a local tree planting initiative.
Bottom line: to sustain our love of forests, take a cue from the ways in which nature has maintained forests over time, including letting some trees go—an important part of the cycle of life.
[Image: A crew works to remove a hickory uprooted by a combination of ivy, termites and Hurricane Irene. Credit: Sarene Marshall]
Sarene Marshall is the managing director for The Nature Conservancy’s Global Climate Change Team. She holds an MBA from the Wharton School of Business and an MA in International Studies from University of Pennsylvania, and is fluent in Spanish. Sarene, a mother of two, enjoys gardening and gourmet cooking.