Tag Archives: climate change

Quaking Aspen in California’s Eastern Sierra

On the eastern side of the Sierra, ribbons of brilliant gold flow down the mountainside. The color can be seen from miles away.  Meadows spread wide covered with vivid yellow-leafed Aspen quaking in a fall breeze. It's the height of the fall foliage season in this part of California.

As I drove down Hwy 89 south of Lake Tahoe past Markleeville and then over Monitor Pass to Hwy 395 each stand of aspen seemed to glow brighter than the last. I wondered if they would be as beautiful for future generations or if our impact on the environment would cause these glorious trees to change in any way.

Quaking aspen (Populua tremuloides) is the most widespread tree species in North America. It provides food for foraging animals and habitat for wildlife. It also acts as a fuel break and retains much more water in the environment than do most conifer species.

High mountain systems, such as the Sierra Nevada, are uniquely sensitive to anticipated global climate changes and act as canaries in the coal mine to provide early signals of significant climate-driven changes. Research in the Sierra Nevada by Pacific Southwest Research Station, which is a USDA Forest Service research organization, shows how vegetation has responded to climate in the past and indicates changes than might be coming in the future over the next decade.

Climate has a profound influence in shaping our environment and natural resources. By looking at tree-ring records of living and ancient wood and pollen lake sediments present climate can be compared to these historic patterns to show climate changes.

Research indicates a complex, unpredictable future for aspen in the West, where increased drought, ozone and insect outbreaks will compete with carbon dioxide fertilization and warmer soils, with unknown cumulative effects. Aspen are valuable in providing moisture in the landscape and habitat and food for wildlife. They are vulnerable in the face of global warming and climate change. Hopefully, we will not lose this wonderful tree in California.

If you're from a part of the country where these trees are native and you miss their fall color there is a new cultivar of Improved Quaking Aspen developed for mild winter areas like ours. It provides a splash of color for areas that are naturally moist like a natural stream or a high water table. They grow 20-30 feet tall and 15 feet wide and spread by underground roots to form a stand.

Gardening in Snow in the Pacific Northwest

It was a snowy afternoon in the Seattle area when I attempted to ferry across the Puget Sound to Whidbey Island. Whiteout conditions got the best of us so we chickened out and decided instead to go to a local arboretum and the garden of one of my sister’s friends. While the snow came down this is what I learned about local gardening in the Pacific Northwest.

This is the home of Lily-of-the-Valley shrub and heather which are blooming now.  Crocus, Siberian iris and narcissus poked valiantly through the snow. Ornamental grasses, not yet cut back, made me think of the prairie in winter. Japanese maples of every type showed off their exquisite form cloaked with a few inches of snow.  Everywhere tall evergreen trees as well as dwarf forms anchored the landscape especially in winter.

The owner of this garden turned a weedy easement that stretched along the entire back fence line into curved planting beds created from retaining walls of beautiful dry stacked local stone. Many low water use evergreen and deciduous shrubs help this gardener in the summertime.  The Japanese maple marks where a utility pole once stood. Snow covered many of the plantings but I can just picture how pretty the spirea and viburnums will be when they bloom in spring.

We grow many of the same shrubs in our gardens as I saw in the Pacific Northwest.  Water conservation is important here, too. Although this area receives lots of winter rain and snow in the mountains by summer’s end, rivers and reservoirs in the Cascades, ground water levels and collected snowmelt reserves are gone. A little rain falls in the summer but it’s still a Mediterranean climate here. Water needs of people compete with those of migrating salmon and other wildlife and vegetation. Climatologists are predicting that climate change may mean less snow pack in the future.

Color in the wintertime is priceless even if it isn’t snowing. It’s too early for the flowering cherries but a few of the plums were starting to show color. Hellebores of every color combination imaginable were blooming in most gardens although the snow weighted down the foliage. Their  flowers stood stiffly upright like the the guards at Buckingham Palace. Bergenia flower clusters braved the weather, too. Some of our common shrubs like ceanothus, abelia, barberry, mahonia, sarcoccoca, hebe, choisya, rockrose and osmanthus are also grown here.

Later, at the in the Emerald City I was treated to fabulous gardens designed using found materials, water catchment techniques, unique paving materials and slope stabilization ideas. One large display garden featured a high mountain forest setting, complete with massive waterfall and huge boulders. A 20 foot tall Japanese maple over a 100 years old dominated one corner. They like things big in this part of the country.

Another favorite garden at the show had us wishing we could transport the whole scene to our own homes. Vintage galvanized pails and wooden flats atop repurposed shelves in a shed with windows created a cozy scene surrounded by roses growing on old wood and wire fencing. Guess you had to be there to experience it’s charm.

As I write this, snow is being forecast for our own area. Maybe it’s following me. I enjoyed my trip to the Pacific Northwest and came back with lots of new ideas but there’s no place like home.