Napa Valley - Enviornment
Napa Valley Environment
Along the Napa River, soil is fertile and well-drained, while atop the mountains concentrations of toxic ultramafic rocks and limited biomatter make growing even grapes - known for their ability to thrive in soil useless for other large-scale agricultural endeavors - impossible. Between these two extremes, the slopes provide plenty of essential nutrients but an environment stressful enough to coax stronger flavors from the grapes grown there.
The climate, too, varies throughout the valley. At latitude 38°, there's generally too much sun for growing high quality grapes, but the temperature is moderated by the Coriolis affect caused by the California Current, which carries almost freezing water from Alaska along the coast, cooling the region. There are five major climate zones in Napa valley (and 15 recognized microclimates), with a variation of 10°F between Calistoga and cooler Napa on any given summer day. These variations in soil and climate have given rise to the distinctive flavors of different wines bottled from the same species of grape in different parts of the valley.
Though the region's relatively sparse population (by Californian standards, anyway) kept Napa Valley relatively free of the anthropomorphic environmental stresses that plague the nearby Bay Area, that has changed in recent years. Large-scale irrigation, fertilizer and pesticide use, cutting forests to make room for more grapes, and rapidly increasing development are all growing concerns. The Napa River and associated watershed are both suffering, while increased tourism has also transformed a rural paradise into a headache for environmentalists.