Unhinged Ecosystem Poses Threat To Rim Communities



Tom Brossart/Roundup


Tom Brossart/Roundup


Peter Aleshire/Roundup

Ponderosa pine forests are adapted to regular, low-intensity ground fires that clear out debris and young trees without reaching the lower branches of the mature pines.


Roundup file photo

The Willow Fire was one of a series of major Rim Country blazes that revealed the danger posed by a forest crowded with more than 1,000 trees per acre across much of the forest.


Tom Brossart/Roundup

A century of fire suppression, logging and grazing has resulted in a dramatic decline in aspen groves and changed the mix of grasslands, oak, juniper and pines.


Tom Brossart/Roundup

A century of fire suppression has resulted in a dramatic decline in juniper and pines — especially along the ecological divide of the Mogollon Rim.

The ancient tree reared, dizzyingly upward, the center pole of a complex, now beleaguered ecosystem. The gigantic ponderosa pine had put down roots before the pilgrims landed, and now stood impassively in a cathedral of giants, sheltering a whole world of creatures. High overhead, a woodpecker scavenged for insects, burrowing through the deep crevices and barked canyons of the giant tree. At my feet, lay the debris of a pine cone scavenged by a tuft-eared Abert's squirrel. I pulled loose a bit of bark, and inhaled the distinctive ponderosa scent of vanilla, a bouquet produced by the complex mix of chemicals that help defend the ancient tree against insects, disease and drought.

The massive pine, too big for two people to encircle with linked hands, was rooted in a dim, sheltered world and crowned in brilliant sunlight. Nourished by mushrooms, assaulted by beetles, battling with mistletoe, harvested by squirrels, perched in by hawks, resistant to fires, and host to multitudes of birds, the enormous “yellow belly” pine was a survivor — not to mention the official tree of Payson.

Once, such giants covered much of northern Arizona. Now, only about 5 percent of the state’s old-growth forests remain, thanks to generations of logging, fire suppression, grazing and development. The old forest hangs on atop a few mountains, in inaccessible canyons, and in a few protected places like the Grand Canyon National Park.

The Rim Country and White Mountains harbor the greatest continuous expanse of ponderosa pine forest in the world, but hardly an acre hasn’t been logged and dramatically altered ecologically.

The surviving big trees are now deeply rooted pawns in a fierce struggle about the future of the public forests. That struggle has evolved like the forest ecosystem itself.

For decades, the Forest Service managed the forest as a giant tree farm — and devoted itself single-mindedly to the prevention of fires. But the passage of assorted laws designed to protect wildlife and ecosystems, the consumption of most of the big trees, studies demonstrating that the Forest Service lost money on most of its timber sales and a succession of lawsuits, gradually shut down the timber industry and all but immobilized the Forest Service. Often, those lawsuits keyed on endangered species like the old-growth dependent Mexican Spotted Owl and the goshawk, since the Endangered Species Act required the government to prevent such species from winking out of existence.

But a decade-long drought, a massive infestation of bark beetles and the frightening spector of massive wildfires has finally spurred a fundamental change in the terms of the debate in many forests.

Increasingly, forest managers, environmentalists and forest users have agreed on the scope of the problem — and the need to find a way to return millions of acres of overgrown forests to health.

Most of those plans involve the return of fire as a management tool, the reinvention of the timber industry to make a profit on the hundreds of millions of small trees that must be removed and the immediate danger to scattered forest communities like Payson, Star Valley, Christopher Creek, Pine and Strawberry — all considered among the most fire-threatened communities in the nation, according to national fire ratings.

Despite the newfound consensus and the move to thin thousands of acres of Rim Country forests, the Forest Service must struggle with contradictory demands and priorities. But the ultimate arbitrator of forest policy remains the ecology of the forest itself — textured and complex as the ridged and crannied bark of a mature ponderosa pine.

Scores of studies by researchers at Northern Arizona University and elsewhere have detailed a complex living network — most of it connected to the biology of old-growth ponderosa pines. The Rim Country harbors hardly a single stand of such giant, old-growth trees — save in the most remote and inaccessible canyons. One participant at a recent forum on forest health in Pine observed that no one living in Rim Country today has ever even seen a “healthy” forest in this area.

The whole forest ecosystem hinges on those majestic, “yellow-bellied” ponderosas, the official tree of Payson.

In that forested landscape, the goshawks eat the squirrels, who eat the cones while spreading the fungi that nourish the trees, that are killed by the bark beetles, who feed the birds while providing nesting snags for the array of birds who feed the goshawk. Any understanding of the public policy dilemmas confronting the Forest Service requires an understanding of this wonderfully complex ecosystem, which has flourished in surprising diversity and flux since the glaciers retreated 10,000 years ago.

“The sum of an old-growth forest is greater than its parts,” notes Northern Arizona University professor Dr. Russ Balder. “The majestic old trees, the diversity, the high stands of grass. Nature wasn’t compartmentalized as it is today in managed forests. That’s how most biological systems work. You can’t understand the forest by looking at its parts in isolation. It’s like looking at individual cells and trying to predict the function of a kidney.”

All these forests are sustained by complex, still poorly understood cycles of growth and decay. One thing we have learned is that all the pieces are connected and interdependent. Each part of the forest affects all the other parts, which is why a pristine, old-growth forest has so much more diversity and resiliency than the vast stretches of same-aged trees produced by logging.

“We need to have all the pieces. If you’re going to maintain something, you’ve got to save all the spare parts,” said Jim Beard, with the Coconino National Forest, an expert on the recreational uses of forests who has documented a huge loss of pristine areas in the past decade.

These surviving pieces of old-growth ponderosa pine forests provide a wonderful study in ecology. This forest is completely dominated by the ecology of these great pines, which cling to soils created largely during the ice age, surviving at the dry, warm limits of their biology. Nature spent millions of years getting the ecosystem of an old-growth ponderosa pine forest just right. Everything fit perfectly: the pine bark beetles, the mistletoe, the goshawks, the black bears, the squirrels, the elk, the mushrooms, the lightning strikes, and the droughts, according to the reconstructions by researchers from NAU.

All those species depended on the gigantic ponderosa pines, which had adapted to the ecological landscape they dominated.

A single tree stood for centuries, hosting one set of creatures in its youth, a new assemblage in its majestic maturity and still others in its sometimes prolonged death. As a massive dead snag, it became the hottest wildlife address in the forest, based on the diversity of birds, mammals and insects that depended on it.

Even after that ancient giant died and crashed to the forest floor, the decaying trunk replenished the soil and fostered a new ecology of rot and transformation across millions of acres of Rim Country forests.

Some trees standing today first put down roots before Europeans settled on the East Coast of an unexplored continent. But that distant landing heralded dramatic changes for the unique ponderosa pine forests of Arizona.

Arizona’s forests in the past century have been utterly remade, thanks to logging, ranching, and the determined suppression of wildfires.

Estimates by researchers from NAU suggest that the forests had just 25 to 75 trees per acre before the state was settled. Today, trees grow at an average density of more than 300 per acre — and more like 1,000 to 1,500 trees per acre across wide stretches.

Many of those trees sprouted in about 1919, which, for reasons foresters don’t entirely understand, was apparently perfect for pine seedlings. But even those higher densities increased about 12 percent between 1962 and 1986, according to estimates by NAU School of Forestry researcher Garrett Anderson. The increase has come almost entirely in the 8- to 17-inch-around category. The number of trees over 24 inches around has declined sharply, and tree-counters have quit looking for trees larger than 36 inches in diameter — the size class that once dominated the forest.

An accumulation of studies has demonstrated how complex and self-sustaining that old-growth ecosystem was, before a century of human policies transformed it.

However, it took forest managers a long while to appreciate the problems they had caused by a century of lopsided management.

The fires that managers devoted themselves to stamping out proved crucial to forest health.

The dead snags the Forest Service paid contractors to cut down proved the center of most bird and insect activity.

The toppled trees the Forest Service sold to loggers proved vital to recharging the soil.

The cattle that seemingly controlled fires by consuming the grass between stands proved essential in eliminating wildfires and producing a dense and unhealthy forest, according to several NAU studies.

The removal of trees intended to increase runoff to streams instead ultimately led to silty runoff that destroyed those streams and the resulting tree thickets starved them for water.

The management of the forests as tree farms led to conditions that ultimately crowded out the timber industry.

The suppression of fire intended to protect towns and settlements instead lured builders out into the forest, then left their developments vulnerable to massive fires.

And all of it stems from the biology of the ponderosa pines, from root to crown.

The cycle of interdependence drawn tight around the mature trees continues even in death.

“These relationships are so intricate,” said Norris Dodd, a game and fish habitat specialist. “In Germany, they’ve been logging for 400 years — the forests are simply falling apart and they don’t know why. Some evidence shows they’ve depleted the soil. If we break these intricate relationships, the bottom line may be that we lose the ability to sustain the system in the long term.”

“It all comes down to nutrient cycling and energy flows,” agreed Dave Patton, an NAU professor of forest wildlife ecology. “We’re trying to understand the interactions of more than 200 different species. It’s so complicated that no one has ever really looked at the whole picture.”

This is the first in a series on forest health and ways to restore it. See part two on Friday.


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