When summer’s flashy circus of wildflowers has passed and the last browned autumn leaf has fallen, an eye looking for signs of plant life is left with the conifers, those stalwart trees that stay green all year long.
Conifers do drop their needles and replace them with new ones—just not all at once. Their ability to photosynthesize all year long gives them a built-in advantage in living in places with a relatively short warm season. So does their natural chemical antifreeze, which prevents needles from freezing even in frigid conditions.
This week Earth Notes concludes its series on the sun with a look at how to use a backyard solar oven. You can use one anywhere there’s a few square feet of sunny exposure on a backyard or balcony.
And yes, you can use a solar oven on some winter days. Even when it’s cold and the ground is covering with snow, a cooker will work if you have enough sunshine and your solar oven is well insulated. But you’ll need to use the midday hours when the sun is at least 45 degrees above the horizon—that means your shadow is shorter than your height.
This week Earth Notes continues its series on the sun, with a look at turning your backyard into a kitchen
Just as the inside of a parked car heats up on a sunny day, a solar cooker traps the sun’s rays in its enclosed interior, causing water, fat and protein molecules in the food to heat up. The molecules vibrate vigorously, and the food cooks.
Since time before memory people have used sunlight to make southwestern homes more livable. Many of the region’s characteristic cliff dwellings were carefully sited in places that are shaded in summer, but sunny in winter. That allowed natural heating to reduce the need for warming fuels.
This month, as nights grow long, Earth Notes pays homage to the sun and to some of the lesser-known ways it can fuel our lives.
It’s well known that photovoltaic solar panels produce clean, renewable energy. But a new study suggests that they can have an unintended consequence: in some climates, panels mounted on roofs may help keep interiors cool in summer and warm in winter.
Each year an average of 250 people are rescued from inside Grand Canyon. Many of them are hikers unprepared for the substantial temperature difference between the top of the rim and inside the canyon. Hikers can be surprised as they start with pleasant 70-degree temperatures at the top and approach a dangerous 100 degrees, or more, near the river.
Now the National Weather Service is working to address that gap in perceptions. With help from the Park Service, it installed two weather stations inside the Canyon: one at Indian Garden Campground, the other at Phantom Ranch.
When it comes to controlling the many non-native, invasive plants in northern Arizona, weed warriors call on every tactic in the book. As they seek to minimize the spread of a weed called diffuse knapweed, they’re turning to a tiny ally: a weevil that loves to eat knapweed seeds.
Diffuse knapweed is a low-growing shrub that originated on the Russian steppes. Since the 1980's, it’s taken over roadsides and pastures in the region. It’s a heavy seed producer and a tough competitor against native plants.
Flagstaff, AZ – Most of the Southwest is hardly turtle habitat. But in the scattered places where water rests in the open, or runs slowly, you can find them in mild weather.
In central Arizona, some of those aquatic animals are Sonoran mud turtles. As their name implies, most live mainly to the south. But Sonoran mud turtles do range as far north as Montezuma Well in the Verde Valley and into Oak and Beaver creeks, where they're fairly common.
Flagstaff, AZ – Toward the west end of Grand Canyon National Park, the South and North Bass trails plunge into wild canyon terrain. The trails are named for William Wallace Bass, a railroad man, miner, and entrepreneur who pioneered the area in the 1880s.
A Hoosier by birth, Bill Bass arrived in the small town of Williams, Arizona, in 1883, seeking better health. Out herding stray cattle one day, he got his first sight of the grandest canyon. "It nearly scared me to death," he declared.
Flagstaff, AZ – Bald eagles are a spectacular sight in Arizona's skies year round. Like the human population, they're more abundant in winter, when individuals from up north migrate south to take advantage of milder winter weather.
Come spring the state is also an important breeding ground for these emblematic birds - and since 1978 their success has hinged on a band of eagle-eyed human caretakers.