Monday, October 17, 2011

Hello...Are You Dead?

National Oceanic & Atmospheric Administration/
Department of Commerce
Exceptional droughts are always a tragedy for someone or something.

In the normally deer-friendly woodlands surrounding the lake near where I live, struggling whitetail does have been forced to abandon their fawns, which roam the park in confusion with their ribs showing. My friend, artist and environmental designer Pablo Soloman, reports that the fawns around his home in the Texas Hill Country have already died.

The trees are going too. Besides vast stretches of woodlands that were charred by the summer's wildfires, significant numbers of trees that have so far remained untouched by flames are dying of thirst. Throughout the exceptional-drought region of Texas and Oklahoma, forest ecosystems—and residential landscapes—are undergoing forced change.

Sometimes, that change can be for the best. Large numbers of invasive eastern red cedar trees are dying of thirst or going up in flames, which will allow native trees, grasslands and wildflowers to resurge. Likewise, the loss of a tree in your yard can present landscaping opportunities that didn't exist before, such as enabling you to plant a more drought-tolerant species or "rearrange" the living furniture to better suit your needs.

But dead, dying, and damaged trees are also prime targets for pests and diseases, which can spread like—well, like wildfire—and compound the loss. So if your valuable trees have suffered visible drought damage such as foliage loss/discoloration, this might be a good time to have them checked out by a certified arborist.

Whether or not the damage is visible, most drought stressed trees have probably suffered at least some root loss. To keep that loss from worsening during continuing dry spells, trees need to be deep-soaked weekly (1 or more inches of water) at least to the outer edges of their drip zones. And they need this supplemental moisture through winter as long as the ground is unfrozen, because while treetops go dormant, tree roots do not.

After one of the most brutal summers ever recorded, I groaned when I heard climatologists warn that the drought still being experienced in the Southern Plains is "just beginning." That's a disturbing prospect, but one for which every property owner should be preparing. [Drought-mitigating measures are covered in some detail in  Weatherproofing You Landscape: A Homeowner's Guide to Protecting and Rescuing Your Plants.] Why should you care if you aren't living in a drought zone now? Because you very well might be living in one in the future, since these unforgiving conditions do "migrate" as complex triggering mechanisms such as La NiƱa come and go.

Unfortunately, for many trees in this "just beginning" drought, it's already too late for even the most urgent rescue measures. While driving through my community yesterday, I counted scores of obviously dead pines, oaks, and other species. Many others were prematurely dropping their leaves, and we won't know until spring whether these were just packing it in for the season and going dormant, or if they too were in the process of dying.

As for my own little corner of the urban forest, I'll continue deep-soaking the big, drought-stressed oaks in my backyard through the coming dry winter. And when the cold season finally draws to a close, I'll hold my breath, waiting—hoping—for the first green buds of spring. Because if you ask a dormant tree if it's dead or alive, that's the only way it can answer.

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