Friday, August 26, 2011

The Great Inland Hurricane

While following the progress of Hurricane Irene up the Atlantic Coast this week... probably assume that hurricanes (typhoons in the Pacific) are limited exclusively to oceans and large gulfs. But even meteorologists were agog four years ago, when mild-mannered Tropical Storm Erin pushed far inland from the Gulf of Mexico...and formed a distinct hurricane eye smack over Oklahoma!

"Hurricane" Erin's winds revved up to 57 mph, with gusts up to 80—a far cry from what Irene is dishing out. Even so, wind velocities were powerful enough to savage roofs, down power lines, and wreak damage over a wide area. But it was the rains, as so often is the case with hurricanes, that proved deadly to seven people caught in flooding.

In an area unaccustomed to rain in such volume, inland residents were caught off guard.

As the storm wallowed over the state, Oklahomans watched their rain gauges fill with alarming speed, and then fill again after they were emptied. Rivers and streams surged out of their banks and into homes, while storm drains turned into white-water rapids.

Even trees reached critical tolerance levels—caught in rushing water, or marooned in waterlogged soil that loosened the anchorage of roots, many simply let go and toppled. And still the rains came, in quantities more suited to the tropics than to the normally dry Southern Plains.

Had Erin been coupled with Irene's higher winds, the damage and loss of life most likely would have been far greater. But the sheer volume of water that flooded onto the plains that day four years ago gave Oklahomans an inkling (a disturbing one, at that) of what more powerful coastal hurricanes can do.

So you folks along the Atlantic Coast: good luck.

Wednesday, August 24, 2011

A Good Walk Spoiled

Over the years, the more I've learned about trees and shrubs, the more I notice the neglect and abuse of those important anchor plants all around me. In many cases, the abuse starts young, with new plants being improperly staked, which can result in lifelong damage. (Most new trees don't require staking at all, except to prevent tipping in windy areas or on sloping terrain.)

But urban trees in particular are subjected to a wide range of tortures that can damage their immune systems and radically shorten their lives. This can include such evils as inept pruning—or no pruning at all—as well as  that all-to-common (and ultimate) crime against trees: topping. They can even do themselves in with root-strangling (surface roots that grow atop their neighbors, effectively chocking them off.) Speaking of roots, another major threat to trees and shrubs involvess root restrictions from pavement, buildings, and other barriers. In addition, let's not overlook root damage caused by pedestrian and vehicular traffic and heavy objects that compress soil within the feeder root zone. And let's not even get into pests and diseases.

In most cases, the abuse isn't intentional; it's simply the result of taking for granted the urban forest that is such an important part of our daily scenery. Before a devastating ice storm "cured" my blindness some years ago, I was as guilty as anyone of this lack of arboreal awareness. No more.

These days, the more I learn about trees, the more difficult it is to ignore what these magnificent plants go through as they struggle to survive, often in extremely stressful circumstances. With eyes wide open, I accept my individual responsibility to, in the words of Dr. Seuss's Lorax, "Speak for the trees."

Becoming tree-aware has enriched my life with a fascinated awareness of—and appreciation of—the lives and complexities of these beneficial giants. But let me tell you, it can also spoil a good walk.

Monday, August 22, 2011

Heat Waves: Worse Than Miserable

Yesterday, we broke our local all-time record for 100F degree temperatures in a calendar year—50 days—and the end is not yet in sight. Down in the Texas Hill Country, artist Pablo Solomon recently reported 63 days above the century mark—and no rain for nine months!

The heat wave of 2011—the hottest summer in the state's recorded history—is beyond just miserable. A nearby wildlife-rehabilitation facility is now caring for more than 100 baby Mississippi kites that had bailed out of their nests because they were roasting up in the treetops. In the opposite direction, the ground has baked so deep that, in our back yard, we discovered a pocket gopher sprawled on the grass beneath an old oak tree that had just been watered. The critter appeared to be luxuriating on the damp soil.

And, oh, those poor trees. Unlike birds and gophers, trees can't go anywhere during unremitting heat waves. As the soil heats up and dries out, a tree's delicate feeder roots dry out too. And the soil doesn't have to dry  very deeply to start causing real damage.

Most of a tree's vital feeder roots are within 6 to 20 inches beneath the surface, spread out up to three times the diameter of the tree's drip zone—the outer edge of its branches. (Deeper "perennial" roots merely anchor the plant to the ground.) All feeder roots are important, but those within the drip zone are absolutely critical.

So I soak that old oak's "critical root zone" during these miserably hot, dry days, making sure the delicate subterranean feeder system doesn't overheat and desiccate. Thus far, the heat-beleaguered tree has hung onto its sparse canopy foliage, while other trees around town have already died. So I assume the oak appreciates my efforts with the water hose. So, apparently, does the gopher.