Hawai'i's Environment
Trees do more than you think
By Jan TenBruggencate
Advertiser Columnist
After Hurricane Iniki rolled over Kaua'i in 1992, things got brighter.
It's not a thing you expect from a hurricane, but it's true. Suddenly the trees had no leaves, few small branches, and the trunks were often snapped off or tipped over.
Residents remember squinting. City streets, back yards, beach parks and roadways were much brighter than they had been.
You could see things you hadn't seen before — good and bad. Hedges are designed in most cases to screen neighbors' views of each other and to screen homes from passing cars. Trees play much the same role. The National Arbor Day Foundation says "Trees are often like good friends: not fully appreciated until they are gone or hurt."
Most trees on Kaua'i survived the hurricane, though many still bear scars. Some died. In forested areas, it is still possible to see the sunburned white trunks of dead trees among the survivors.
The Arbor Day folks recently listed some of the ways trees help the community.
A screening tree or hedge not only adds privacy, it can cut noise by 3 to 5 decibels.
By attracting songbirds, trees additionally reduce unwanted noise from cars, heavy equipment, yelling kids and adults and other annoyances of urban life.
They cut energy costs by shading homes from the heat. The temperature under a tree can be several degrees cooler than in the sun, and a shaded wall makes the room inside distinctly more comfortable than one with the sun blazing on it.
Trees capture dust from the air and release oxygen, providing a twofold benefit for humans.
In many areas where leaf litter is allowed to remain, a tree creates mulch that helps reduce rain runoff and improves ground moisture.
In the native dryland forest at Kanepu'u on Lana'i, the leaf litter is thick, and there is moisture in the soil even during extended droughts. Walking beneath the trees is a cool experience, a stark contrast to the hot, dry, dusty world of the treeless, eroded slopes just a few yards away.
The Arbor Day Foundation report suggests that trees contribute to the economy as well, adding value to commercial and residential areas.
"Studies conducted in two communities in New York and Connecticut showed that the presence of trees increased the selling price of homes by as much as 15 percent," it said.
When an ice storm in 1993 killed many of Cincinnati's trees, citizens donated money to plant 2,000 new ones.
Learn more at the Arbor Day Foundation's Web site.
Jan TenBruggencate is The Advertiser's Kaua'i bureau chief and its science and environment writer. Contact him at (808) 245-3074 or e-mail jant@honoluluadvertiser.com.
