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Down on the Ground with the Troubled Trees

By George Sibley

The onset of the wildfire season puts our forests back on the front page, but the wildfires are really just a visible symptom of larger troubles among the trees – troubles that track those “natural disasters” right back to us humans and some naive cultural choices.

Humans have always had a complex, extensive and intensive relationship with trees. Personally, I grew up back east, where human settlement was synonymous with clearing the forest, but I can’t imagine living in a place without trees that are taller than I am. When the Euro-Americans came west to the mostly treeless drylands, they brought trees with them. Gunnison was a sagebrush flat, but its founders immediately laid out a grid of irrigation ditches along with the grid of streets, and started growing trees as fast as they grew saloons.

I once found an old forestry textbook in a yard sale, which I bought solely because thumbing through it, my eyes fell on this statement: “A tree is a living organism, complex in its structure, and not entirely understood yet as to its function.” What struck me about that – there is not a word in that statement that is not also true for us humans, we are living organisms, complex in our structure, and who could pretend to entirely understand our function here? But I would say with some certainty, that our function on the planet is intimately tied to the function of the trees.

Historically, humans have depended on trees in order to function at all. Until relatively recently – and this is still true for much of the world – trees were our principal energy resource (along with hay for our horsepower). We had known about coal and petroleum for centuries, but found them messy and hard to access; it was only when Europe and England suffered a major energy crisis during the 16th and 17th centuries that we were forced into seriously mining the fossil fuels.

Mostly, we take for granted other useful functions the trees perform for us. The boards and beams that make up most of our built environment were once trees, although probably most of us deplore the sight of a logged-over area when we come upon one. (Gifford Pinchot supposedly said, “People who live in wood houses shouldn’t throw stones at loggers.”) We are also at least semi-consciously aware of the way trees comb some of the violence out of wind and sun, and cool their immediate vicinity through leaf evapotranspiration. We know that trees inhale some of the carbon dioxide we and our machines exhale, and exhale the oxygen we need.

Beyond all that usefulness, we love them for their beauty; many of them are just lovely companions around the neighborhood, some inspire us with their stately endurance, and some awe us with their size and age. Life is just better with trees. And in the balance, in terms of our mutual if incompletely understood functionality, we undoubtedly need the trees more than the trees need us.

Noting all of that, however, makes it even harder to face the fact that most of the trees here in the Southern Rockies are struggling today – and we, who benefit from them and love them, have caused most of their problems, primarily through not understanding our function with respect to theirs.

A big misunderstanding, for example, is Smokey the Bear’s century of hard work to save the forests from the fire they might not want, but do need. Trees, like humans, optimistically overpopulate their environments in good times, and pay with mortality in not so good times; but here in the arid regions of the so-called Temperate Zone, a cool dry climate slows the active recycling agents of the resurrection through rot. Dead stuff piles up, and a forest of trees needs fairly regular episodes of “rapid oxidation” – fire – to balance life and death in the forest. If fire happens regularly enough, here and there in a forest on a modest scale, the forest is cleaned up in a kind of mosaic pattern of burned patches with new growth seeded from adjacent unburned areas, which in turn need cleaning up and either get the random lightning or don’t.

We could help the forests by making that patchwork pattern of limited destruction less random, and even helping it along – which we are beginning to do. But we didn’t look that deeply a century ago; we just couldn’t bear to see both the waste of wood (utility) and the temporarily blackened zones (aesthetics), so we made it a policy to fight all fires when we could. What we managed to do – and I speak from down on the ground as a former forest firefighter – was put out the little fires that would have cleaned up a piece of the forest, thus helping the fuel loads accumulate for big fires that consumed nearly all life in entire forests despite the expensive efforts of armies of firefighters.

Throughout the century, while that exercise in naïve futility was going on, we were steadily and relentlessly, if only semi-consciously, converting carbon solids and liquids that had been “banked” in fossil deposits for eons into greenhouse gases that have changed the climate of the whole planet, making the atmosphere warmer and less stable almost everywhere. More warming is almost certain to come, given that we can’t even consensually face the fact that it is happening. Greenhouse gases continue to increase, albeit at a slower rate.


[InContentAdTwo] This is having a serious impact on our functional partners, the trees, especially here in the mountains. Average temperatures decrease naturally as altitude increases, and different species of trees have different tolerances for heat and cold – often a fairly narrow range of tolerance. So different tree ecosystems prevail at different altitudes, but those altitude zones are now – not in the future, but now – shifting upward as the climate measurably warms.

The impacts of changing climate are being intensively studied, with mostly disheartening findings. Foresters hypothesized, or maybe only hoped, that as average temperatures increased, the tree species would also gradually shift uphill, abandoning their lower, too-warm reaches and moving into territory abandoned by the higher-altitude species also warmed out by the changing climate. The trees themselves do not move uphill; they gradually fail and die in their lower forest reaches, leaving a mess that wants either a fire or a salvage logging (which will, of course, be opposed).

This upslope transition will in fact probably happen, but not quickly or smoothly. Each species has a unique microbiome of bacteria and fungi in the soil that enables its success, and that has to establish itself in places already haunted by the old species’ biomes and carcasses. The pace of natural change is unfortunately slower than the pace of warming, which may affect it happening at all. Tree zones might shrink from the bottom but not advance above.

Another hypothesis, or hope, was that as the atmosphere warmed, trees would grow faster and larger, and their growth would absorb more of the carbon gases in the atmosphere and offset some of the consequences of climate warming. Much of that hope was hung on the vast boreal forests that stretch across the sub-arctic regions of North America and Asia where temperatures are expected to rise more than in the temperate zone, but scientists thought – hypothesized, hoped – that it would happen with trees everywhere.

A 2016 study of all North American forests indicate that this is apparently not only not happening as hoped; the opposite may be happening. According to one of the University of Arizona-based researchers, “We don’t see any greening in our results. Instead, we see browning … Trees in very high latitudes are limited by cold temperatures, so yes, in warmer years they grow more, but there is a tipping point, and once they go past that, a warmer climate becomes a bad thing instead of a good thing.”

So there we have it. The trees are in trouble – mostly trouble we’ve caused for them. Although it’s compounded by the common problem we share with the trees of assuming the good times will just roll on, and then not so good times nip us all in the ass with too many of us depending on too small a resource base. What to do?

For me, it comes down to the question I keep ending with here: whether we are to be the planet’s gardeners, continuing to try to find a more functional order in the complex living systems life has pasted over the planet’s elemental chaos, or whether we are just guardians protecting what’s left of the evolving systems from our further meddling, and letting natural systems work out their own new dynamic balance, with or without us. Friends, whom I respect, argue both ways – and why not: We are, after all, like the trees, living organisms, complex in our structure, and we don’t seem to understand our own function any better than we understand the trees’ function. Gardeners or guardians? “I talk to the trees,” sang the old prospector in Paint Your Wagon, “but they don’t listen to me.” Wonder what the trees would say if we could or would listen to them?

George Sibley lives in Gunnison and listens to anything that will talk to him –