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Sequoia and Kings Canyon National Parks. Mike White
Читать онлайн.Название Sequoia and Kings Canyon National Parks
Год выпуска 0
isbn 9780899976730
Автор произведения Mike White
Жанр Книги о Путешествиях
Издательство Ingram
Wildflowers near Golden Trout Lake (Trip 104)
Spring and early summer may bring a colorful display of wildflowers, including drought-tolerant species like paintbrush, lupine, and mules ears, to the woodland.
Along the banks of eastern Sierra streams in this zone, a dense display of wildflowers, shrubs, and trees flourish in stark contrast to the area immediately outside the riparian zone. Quaking aspen, cottonwood, willow, oak, birch, and ash are common streamside trees, which may intermix with conifers from the forest zones above. Currant, wild rose, and a variety of willows are typical riparian shrubs.
Animal Life: A wide variety of amphibians, reptiles, birds such as the sage grouse and red-tailed hawk, and insects find a home in the pinyon-juniper woodland, as do an assortment of mammals. Small mammals, including several species of mice, squirrel, vole, rabbit, shrew, and chipmunk are quite common. Larger mammals, such as the coyote, skunk, badger, and mule deer, are familiar residents as well. Coyotes (Canas latrans) subsist as omnivores on a wide-ranging diet. Their whelps and howls are commonly heard after sundown.
Sagebrush Scrub
Plant Life: Fortunately, only a few east side trails pass through the extremely hot and dry conditions found in the sagebrush scrub zone. This zone receives less than 12 inches of precipitation per year, most of which falls during the winter months. Occasionally, a welcome thunderstorm waters the parched ground and produces the characteristically pungent aroma of wet sagebrush.
At first glance, the gray-green sagebrush creates a seemingly unbroken band of vegetation across the lower foothills above Owens Valley. However, closer inspection reveals a diverse flora, including a mixture of bitterbrush, rabbitbrush, desert peach, and spiny hopsage interspersed within the sagebrush. Before native perennial grasses were overgrazed and replaced by invasive annuals, a healthy mixture of bunchgrasses filled the sagebrush scrub zone. After uncommonly wet winters and springs, the high desert produces a vivid display of wildflowers from late spring into early summer.
Animal Life: Animals found in the sagebrush scrub zone are similar to those found in the pinyon-juniper woodland zone.
Geology
Although the origins of the Sequoia and Kings Canyon regions are somewhat speculative, geologists have determined the composition of the rock forming the area’s soaring peaks and deep canyons. Even a cursory examination by the untrained eye reveals granite to be the overwhelming rock type in the High Sierra. These light-colored, salt-and-pepper speckled, coarse-grained rocks include granite, granodiorite, and tonalite (formerly referred to as quartz diorite). These rocks also contain varying amounts of minerals such as quartz, feldspar, biotite, and hornblende.
The Sierra Nevada Batholith, a term geologists use to describe the massive pluton of rock forming the range stretching 300 miles in length and 50 miles in width, was formerly a band of molten magma below the earth’s surface. The magma eventually cooled and crystallized, and was subsequently uplifted and exposed to form the Sierra Nevada as we know them today.
A much smaller percentage of rock in the Sierra is metamorphic. Typically dark in color and variegated in appearance, metamorphic rocks are considered older than the much more common granitic rocks. Remnants of these rocks are scattered across the Sequoia and Kings Canyon region, and four distinct metamorphic terranes have been identified. A number of caves, including Crystal Cave near the Giant Forest and Boyden Cave near Kings Canyon, were discovered in concentrations of marble, a type of metamorphic rock.
An even smaller percentage of the region’s geologic composition includes volcanic rock. Within park boundaries, this rock type is nearly nonexistent, the lone exception being a very old volcanic intrusion near Windy Peak along the Middle Fork Kings River. Smatterings of other volcanic activity are evident in small pockets west of Kings Canyon and southeast of Sequoia near Golden Trout Creek. The most noticeable evidence of volcanism in the area occurs east of Kings Canyon National Park in the Big Pine Volcanic Field, where passing motorists on US Highway 395 can easily see cinder cones and lava flows.
The Sequoia and Kings Canyon area is home to some of North America’s most impressive canyons. Modern geologists recognize the importance of both erosion and glaciation in the formation of these canyons. In the lower elevations, the erosive power of water is clearly evident, resulting in V-shaped canyons, such as the lower South Fork and Middle Fork Kings River. The characteristic U-shaped canyons cut by former glaciers are found in the higher elevations.
Speculation on the role of glaciers in the sculpting of the upper canyons of the Sierra Nevada is as old as John Muir himself, who proposed the notion back in the late 1800s. Whatever the extent of their importance in the past, today’s glaciers occupy a very small percentage of territory in the uppermost realm of the High Sierra (usually above 12,000 feet on the north and east faces of the highest peaks). Despite their lack of size, these remaining glaciers add a touch of alpine beauty to these otherwise rocky mountains, The largest glacier in the Sierra is Palisade Glacier, a pocket of ice less than one square mile in size.
Negotiating talus on the Lamarck Col cross-country route (Trip 121)
Backpackers negotiate the snow-covered trail on the way to Bishop Pass (Trip 103)
Climate
The Sierra Nevada experiences a wide range of weather within the four seasons, which greatly affects the recreational opportunities for exploring this majestic landscape.
Summer
Most visitors to Sequoia and Kings Canyon National Parks and surrounding wilderness areas come to the region during the summer months. Compared to many other North American mountain ranges, the Sierra Nevada is typically blessed with an abundance of mild, dry, and sunny weather. Summers are particularly fine, as 95 percent of the annual precipitation falls between November and March. Occasional summer thunderstorms account for the remainder, but they occur with much less regularity than in the Rocky Mountains, for instance. Summer temperatures are generally mild. However, they vary considerably from the foothills to the alpine heights.
When the snow has mostly melted in the highest parts of the Sierra, backpacking season begins in earnest. Warm weather usually persists in the High Sierra from mid-July into September. Although summers in the Sierra usually bring dry, sunny days, thunderstorms are not uncommon, particularly in the month of July, requiring backpackers to be prepared for fickle weather conditions. Usually thunderstorms resolve fairly quickly, but infrequent monsoonal storms lasting two to three days or longer are not completely out of the question. Afternoon highs during summer often creep up into the high 60s and low 70s in the high country, although the temperature may actually feel much warmer due to the increased solar radiation prevalent at higher altitudes. July is also when the mosquito population explodes, with a peak usually lasting over a two-week period. If you plan a trip for July, be sure to pack plenty of repellent and bring a tent.
Early to mid-August is the prime time for backpacking because thunderstorms are less common, a major frontal system is unlikely to affect the area, and the mosquito population has abated to a more manageable level. Lakes in the High Sierra, although rarely warm, are not as cold as earlier in the summer, offering refreshing opportunities for an enjoyable swim. Late August into early September brings less daylight, pleasant but slightly cooler temperatures, and far fewer mosquitoes. By then, the wildflower season has passed its peak and the meadows have started to dry out, but fewer people are on the trails.
Autumn