This young whitebark pine shows the classic shape of a tree brutalized by winter ice blast. The bottom branches are protected by the snow, but the upper branches are exposed and absorb the full force of the wind-driven ice, creating the narrow top.
As the Christmas Day storm raged, I spent most of my day huddled inside. I ventured out long enough to fill the bird feeders and to clear the driveway of snow three times, but mostly I just wanted to stay out of the sting of wind-propelled snow and ice crystals.
On such a day, I am particularly grateful for a warm home and my thoughts invariably stray to organisms that cannot simply turn up the thermostat when it is cold. Some can avoid winter but others, particularly sub-alpine trees, bear the full force and fury of the season and somehow survive.
While cold is winter’s overlord, its minions are wind, snow, ice and frost. Each of these can play a role in which plants live, where they live, their shape and even the basic structure of a sub-alpine ecosystem.
Wind, more specifically, wind-driven ice particles called ice blast, is the sculptor of many sub-alpine trees. The windward side of large alpine trees such as limber pine, bristlecone pine and whitebark pine, has bark that is highly abraded by ice blast or bark that is missing altogether. The wood of older trees may be shaped and smoothed just as wind-blown sand can create holes in sandstone.
Wind-driven ice is fiercest just above the snow level. Wind scours the surface of the snow, plucking away ice crystals and hurling them against nearby trees. Mop headed trees develop where the branches beneath the snow are normal, but those above the snow are severely eroded or absent altogether. The mop head, a cluster of branches at the top of the tree, eventually forms as the tree grows beyond the reach of the surface-generated ice blast. Even then, the “mop head” may only have live branches and needles on the lee side of the tree.
When the wind doesn’t blow, snow buildup can become the enemy. Snow is heavier than it looks. I still marvel that the weight of snow can pull fences down and snap heavy wire. That same weight can build up on trees creating snow loads that may strip branches and even snap off entire trees. Conifer trees, with their narrower shapes and down sloping branches, tend to shed snow when it builds up, but that is not always the case. A combination of snow and ice build-up may weigh over 6,000 pounds on a 40-foot-tall tree in some places.
Even deciduous trees suffer. For instance, it is rare for native aspens to retain branches below the average snow level because the weight of the snow prunes them off.
Snow is such an important part of the overall ecology in sub-alpine areas that it is even responsible for shaping some forests. Called ribbon forests, they form when snow drifts form on the lee side of tree stands. These drifts persist well into summer, denying conifer seedlings a chance to start. The result is lines of forested areas separated by meadows in often a precise pattern.
The cold temperatures drive the frost deep into the ground. There, the effect can be dramatic. The ground freezes in horizontal layers that cause the soil to heave or bulge. When this happens, entire plants may be uprooted.
When the storms rage, I’ll take the comfort of my centrally heated home over an sub-alpine blizzard. It is fascinating to note, however, that while winter conditions can be severe in the high country, plants have found ways to survive and thrive.
Donate part of your tax return to support wildlife in Idaho!
On the second page of the Idaho Individual Tax form 40 you have the opportunity to donate to the “Nongame Wildlife Conservation Fund”.
Check-off this box on your next return or ask your tax preparer to mark the Nongame check-off on your behalf.
If you are not from Idaho, check with your own state wildlife agency about how you can help. Many states have a similar program.
"WOW. What a phenomenal piece you wrote. You are amazing." Jennifer Jackson
That is embarrassing but actually a fairly typical response to my nature essays. Since The Best of Nature is created from the very best of 16 years of these nature essays published weekly in the Idaho Falls Post Register (online readership 70,000), it is a fine read. It covers a wide variety of topics including humorous glimpses of nature, philosophy, natural history, and conservation. Readers praise the style, breadth of subject matter and my ability to communicate complex and emotional topics in a relaxed and understandable manner.
Everyone can find something to love in this book. From teenagers to octogenarians, from the coffee shop to the school room, these nature essays are widely read and enjoyed.
Some of the essays here are my personal favorites, others seemed to strike a chord with readers. Most have an important message or lesson that will resonate with you. They are written with a goal to simultaneously entertain and educate about the wonderful workings of nature. Some will make you laugh out loud and others will bring a tear to the eye and warm your heart.
"You hit a home run with your article on, Big Questions in Nature. It should be required reading for everyone who has lost touch with nature...great job!" Joe Chapman
"We enjoyed your column, Bloom Where Planted. Some of the best writing yet. The Post Register is fortunate to have your weekly columns." Lou Griffin.
To read more and to order a copy, click here or get the Kindle version
Copies are also available at:
Barnes and Noble in Idaho Falls
Perfect Light Photo Supply
Museum of Idaho
Valley Books, Jackson Wyoming
Avocet Corner Bookstore, Bear River National Wildlife Refuge, Brigham City, Utah
Craters of the Moon National Monument Bookstore, Arco, Idaho