Review by Ed Quillen
Nature – February 1997 – Colorado Central Magazine
Land above the Trees – A Guide to American Alpine Tundra
by Ann H. Zwinger and Beatrice E. Willard
Line drawings by Ann H. Zwinger
Published in 1996 by Johnson Books
When I get above timberline, the biology looks pretty much the same in all directions except down — just grass among the jagged rocks, perhaps some wildflowers in season, and a few pikas scurrying about, making hay while the sun shines, while the marmots, once they get over their shyness, come over to beg food from my pack.
But as Ann Zwinger and Beatrice Willard make abundantly clear in Land Above the Trees, the zone between the trees and the sky is much more complex.
The apparent uniformity of the highest country is an illusion, for there are no fewer than nine different biological zones you might encounter at 12,000 feet and up: treelimit and krummholz, boulder fields, talus and scree slopes, fellfields, alpine meadows and turfs, snowbed and snow communities, animal-disturbed communities, alpine marsh and lake communities, and alpine heath communities.
The authors caution us that although the other eight communities are well represented in the Southern Rockies we won’t find much if any alpine heath in Colorado, which has more land above timberline than any other state.
They prefer treelimit to timberline, a term from logging days that refers to big, straight trees worth cutting, rather than the twisted and tiny krummholz at the treelimit.
At those elevations, the limits to growth are generally imposed by the relentless wind, not by year-round frost or the rarefied atmosphere.
Plants adapt by seeking shelter among the rocks, and by performing most of their metabolic chores in the six or eight chilly weeks of alpine summer. Hereabouts, most are perennials — there’s only one annual in the Southern Rockies.
Land above the Trees is organized in two major sections. One details each of the nine communities, and the other explores the alpine areas of the lower 48, each with its own quirks — our Southern Rockies, the Presidential Range in New England, Great Basin ranges, Northern Rockies, Northern Cascades, Olympic Mountains, Southern Cascades, and Sierra Nevada.
The winds are strongest in New England, the Cascades get a lot more precipitation, and the southernmost of the Rockies, as well as the Great Basin peaks, are “islands” isolated from other alpine zones.
Even so, they hold much in common, and with the end of the Cold War, our scientists have been able to visit previously inaccessible areas in Russia to discover that the same plants and animals thrive in the highest country of the Old World.
I found this book fascinating, but it’s best taken in small chunks. I don’t know of other works by Beatrice Willard, but I’ve read much from Ann Zwinger. Her writing is exquisite, but it’s also like a rich dessert. A little at a time is a delight, but past that, I start to feel overwhelmed. Here’s an example:
Summer snow surface has quite uniform conditions: low air temperature, high intensity of reflected light and a great abundance of blown-in organic matter along with high humidity. Although the layer of air just above the surface may be dry, the prevailing low temperatures and evaporation from the snow lessen the risk of desiccation for insects that feed there, and most of these can absorb warmth from the direct sunshine without injury. There are usually various kinds of flies, several species of spiders, and multitudes of mites and springtails. One of the most primitive of insects, springtails have a kind of tiddlywink arrangement on their abdomens that allows them to pop across the snow like water on a hot griddle. They browse for pollen, spores, and debris, forming the basis of a food chain which culminates with the foraging birds that imprint three-tined tracks across the snow.
The illustrations, line drawings by Zwinger, are somewhat like the prose — rich, detailed, and informative. I found them so intriguing that they seem to transcend illustration and become little works of art, adorning dozens of pages.
Land above the Trees is not light reading, and it’s not a light book either — 22 ounces. But it is of a convenient size, and the binding and paper seem quite sturdy, so it should fit well into a hiker’s pack.
At least, I plan to put in my day pack when the weather gets better. The book opened my eyes to the biological treasures that I’d been hiking past for years, just assuming that I was in a bleak and windswept landscape with little to offer except the prospect of gazing down from whatever summit I was gasping to reach.