California's lost wildflower fields

When Spanish explorers arrived in the late 18th century, vast meadows of wildflowers carpeted California along coastal plains and valleys in the lower two-thirds of the state and inland to the Central Valley, according to a new book by UC Riverside ecologist Richard A. Minnich. Now these areas, once replete with poppies, tidy tips, fiddlenecks, phacelia, popcorn flower, lupines and owls clover, are covered by European exotic grassland.

In the book, California's Fading Wildflowers, published by the University of California Press, Minnich chronicles how species introduced by Franciscan missionaries, such as black mustard and wild oat, had extensively displaced native plants by the Gold Rush. But then interior flower fields were muscled out a century later by red brome, ripgut brome and slender wild oat.

Minnich's research delved into accounts from 19th century botanists such as John Muir, as well as Los Angeles Times newspaper reports from the early 20th century. And he discovered that it was untrue, as many have assumed, that the original vegetation consisted of grasslands that were later destroyed by overgrazing. "California's wildflower heritage has been overlooked because of a flawed hypothesis that bunch grasses were pervasive in the past," he says. "We take for granted the rapidly fading wildflower heritage because the perception of past vegetation among the scientific community and the public has been built upon this erroneous premise."

Today, Minnich says, "you hardly see wildflowers, and when you do, they appear in patches here and there, not as meadows that once characterized the state."

Invasive plant species not only destroyed California's botanical heritage but also create a fire hazard, according to Minnich. He advocates new management strategies, including spring burning, seasonal grazing by livestock and use of Old World pathogens as biological controls of invasive species.

-- Margot Roosevelt

Photo: A poppy field near Lake Mathews. Such fields were once far more extensive. Credit: Richard Minnich