It was amazing to be skiing in late
April, in Wisconsin, and it is amazing that I can begin yet another Natural Connections by
describing an experience on the ski trail. This particular day, with its
bluebird sky, bright sun, and warm temperatures, also reminded me of another
spring ski in a faraway land called Utah.
Back in 2005, I did an internship with
the National Park Service leading school field trips and working in the visitor
center in the Needles District of Canyonlands National Park. I lived in the
tiny little town of Monticello (very similar to Cable!) at the base of the
Abajo Mountains. Even though their name means “low,” the mountains tower above
the intricately carved sandstone canyons of the park.
One weekend, my roommate and I took
our skis and drove up the mountain road to where the snowplows stopped. From
there, we skied up and over the snow-packed pass, and stood breathless at the
view. From the midst of winter, we looked out on a sunbaked summer landscape of
red rock canyons below fluffy white clouds. The view fueled our anticipation
for spring. The only thorn in my day was cracked lips from the desert-dry air.
You might not think that Wisconsin and
the desert southwest have much in common, but I found enough similarities in
Utah to feel at home there, too. The snow, for one, was a nice connection. And
half-buried in that snow were manzanita bushes with small, waxy, evergreen
leaves on short woody stems. They bore a family resemblance to their cousins,
other plants in the family Ericaceae, who are some of my favorite residents of
Wisconsin bogs.
If you’ve ever explored a bog, you may
have noticed that quite a few plants have those small, waxy evergreen leaves.
Leatherleaf’s name advertises its tough appendages, while the lovely names of
bog rosemary, bog laurel, small cranberry, and snowberry contrast with their
hardy leaves. All are in the Ericaceae family.
Down in the desert canyons, the fuzzy
leaves of sagebrush, Indian paintbrush, globemallow, and the in-rolled leaves
of mountain mahogany also reminded me of my Wisconsin home. That might seem
odd, but have you looked at the underside of a Labrador tea leaf from your
local bog lately? The leaf margins roll in on a dense patch of wooly orange
hair, and hairs also carpet the tightly-curled leaves of its neighbor, bog
rosemary.
Why might desert plants and bog plants
have some characteristics in common? For one thing, they both deal with a lack
of water and desiccating winds during at least part of the year. But aren’t
bogs soggy? Well, yes, but not when they are frozen, a condition that can
extend late into spring. Plus, sometimes the peat in bogs builds up so much
that plants are elevated above the water table. Deserts and bogs are also poor
in nutrients due to slow decomposition rates.
Evergreen leaves are great for
contending with low nutrient availability and short growing seasons, because
plants do not need to grow new leaves each year, so they are less dependent on
nutrients getting recycled. However, unlike deciduous leaves, evergreen leaves
must deal with the absence of liquid water in winter (or in the summer for that
matter.) The thick, waxy cuticle is a plant’s first defense, since it reduces
water loss from evaporation. It serves the same purpose as the beeswax-based salve
I massage into the cracked, dry skin of my heel and lips. This protective wax is
as useful in Wisconsin winters as it is in Utah!
Although waxy leaves help protect them
from drying out, plants still need to exchange some gases through their stomata
to carry out photosynthesis. Stomata are pores in the leaf that allow gas
exchange. Along with taking in the carbon dioxide necessary for photosynthesis,
water vapor can also escape during transpiration. To reduce this loss, plants –
both here and in the desert – try to create a “boundary layer.”
The boundary layer is a thin zone of calm
air hugging the surface of the leaf. In this layer, the conditions are less
harsh (less hot and dry) than in the wider world, and the temperature and
moisture gradient is less steep. Therefore, the larger the boundary layer, the
slower the rate of water loss. Hairy and in-rolled leaf margins increase the
size of the boundary layer and slow water loss from transpiration. Humans
create our own boundary layers with fuzzy wool sweaters and fleecy mittens.
Today
we stand in Wisconsin – on the edge of winter – admiring the view of a distant
spring. Although it may look quite different from southeast Utah, similarities
can be found across all communities if we are willing to look a little closer.
This holds true in our human communities just as much as in our natural
communities. Where can you see our own Midwestern toughness and resilience
reflected around the globe?
“It is a wholesome
and necessary thing for us to turn again to the earth and in the contemplation
of her beauties to know of wonder and humility.”
--Rachel Carson
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