BEACONREADER.COM 10-23-14 CO A Rocky Mountain EcoFlight

Oct 23, 2014

A Rocky Mountain EcoFlight

BOB BERWYN

An expanse of quilted forest, with stands of aspens in lingering fall colors and conifers on the steeper and shadier north-facing slopes. When I first looked at this image, I thought the blue-gray evergreens on the right side of the picture were spruce trees, mixed in with the brighter green of fir and lodgepole pine. But when I magnified the image, I realized that those are the gray ghosts of beetle-killed trees, still standing among the living forest. Observing the forest from above gives you a clear idea of how sensitive forest boundaries are to climatic conditions in this mid-continental, semi-arid climate. There are distinct boundaries which are clearly shaped by climate conditions like temperature and precipitation. Any significant changes to those parameters will result in shifts in the forest pattern.

A vivid pattern of golden aspens, reddish-orange scrub oak and bright green irrigated pasture against a backdrop of gray-green sage. Earlier snowmelt and peak runoff will require ranchers to change their irrigation practices, and will also affect riparian plant and animal communities in Rocky Mountain drainages, which are often like lifelines in an otherwise semi-arid landscape.

Flying low over the Eagle River Valley, we had a chance to see how the human footprint fits into the mountain landscape. In the case of this golf course community, very little of the natural terrain remains. I-70 and the Eagle River slice through near the top of the image.

So let’s zoom out for a minute and take a look at the Rockies from NASA’s Aqua satellite, orbiting the Earth at an elevation of about 700 kilometers. Western Colorado and Utah are almost completely covered with snow, except for the deep canyons in southeastern Utah after big December 2012 snowstorm, and you can see a tiny slice of the Southern California coastline in the bottom left corner of the image. These deep and widespread midwinter snows sustain much of life as we know it in this part of the world, accumulating all winter long, then melting slowly in the spring to replenish rivers, lakes, wetlands and reservoirs. At the heart of it all is the Colorado River. Can you spot its winding path from western Colorado through the snaking canyons of Utah, across Northern Arizona and defining the southern tip of Nevada? A recent Department of Interior study suggests that global warming will reduce flows in the river substantially by the end of this century. The river likely won’t be able to deliver all the water that’s been claimed by the various states, and as water shortages grow, like in this year’s California drought, conflicts between states will only be avoided if there’s upfront planning and collaboration, with the recognition that global warming will take a big bite from our water supplies, whatever else we do.

Early morning light casts a beautiful golden glow on these mid-elevation aspen stands, sheltering a small pocket of conifers near the summit of this broad western Colorado Plateau. Aspens are among the most widespread tree species, but they’re also sensitive to variations in annual and seasonal precipitation. A massive aspen die-off in the early 2000s was triggered by a relatively short, albeit intense drought. Even without human-caused global warming, ancient tree rings tell us that this region has seen sustained decades-long dry spells that would fundamentally change the distribution of trees across the Rocky Mountain landscape. In areas like where this photo was taken, aspens could easily be replaced by sagebrush steppes. Read more about how global warming is affecting Rocky Mountain forests in this Beacon story.


Aspens are clonal organisms, meaning they sprout mostly from existing roots of living trees, or sometimes from roots that have been long buried and inactive, but are suddenly stirred by some natural event like a fire or an avalanche. The picture above shows how the patches of aspens appear to be separate distinct organisms. Clonal reproduction offers aspens some big advantages in their ecosystem niche, but also makes the species more susceptible to catastrophic events.

Looking south from above I-70 toward the Holy Cross Wilderness Area. Most existing national forest wilderness areas are at high elevation, in the realm of rock and ice. The most recent round of proposals, bottled up in Congress, would include some lower-elevation areas in western Colorado that are critically important to protecting wildlife, water and other natural resources from the encroaching impacts of human development and climate change.

There are still plenty of healthy forests in the Rocky Mountains, as seen in the previous image, but in the San Juans, spruce beetles have ramped up their reproduction and killed vast swaths of spruce trees, shown in this U.S. Forest Service aerial survey photo taken during an annual mission to document forest health.

In western Colorado, a lot of the Rocky Mountain runoff goes to irrigating alfalfa, seen bundled here after this summer’s rains brought a bumper crop. Many of the irrigation water rights in the region are very old, and help regulate the flows of rivers upstream of the diversions. In other words, when a rancher near Grand Junction calls for his water, it helps ensure flows near Glenwood Springs, where the water is important for rafting and fishing.

A sprawling exurban subdivsion near Eagle, Colorado, butts up against the wild edge of the Rocky Mountains.

Ridge-top McMansion development in Eagle Country fragments the landscape and wildlife habitat.

Sprawling aspen groves growing on mid-elevation BLM land that’s currently under a wilderness study area designation. Several wilderness bills pending in Congress would add some of these areas to the official wilderness roster.

Looking north toward the strip development zone along I-70 in the Eagle River Valley.

Puzzling together the landscape from above, trying to connect the natural drainages with irrigation channels, leading to irrigated pastures and hayfields (upper right).

Forests are veins of life in the Rocky Mountain landscape.

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