Our forgotten landscape: California prairie

Here's an interesting take on California's grasslands, which appear to not be quite so grassy as the name would lead you to believe. Since I live one block from a street named "Prairie" and have seen historic photos of the nearby prairie, this has particular interest to me.

This is copied in its entirety from the Daily Democrat. The author refers us to www.tuleyome.org for additional information, so I'll be browsing around there looking for some more interesting articles.

Our forgotten landscape: California prairie
By GLEN HOLSTEIN
Created: 09/06/2009 02:30:42 AM PDT

John Muir, California's greatest naturalist, taught America and the world to love and preserve nature rather than use it up. Muir arrived in San Francisco in the spring of 1868 and walked south through the Coast Range.

At Pacheco Pass he descended to the then unplowed Central Valley. He found "one ... bed of [flowers], so marvelously rich that, in walking... 400 miles, your foot would press a hundred flowers at every step. "Here it is not as in our great western prairie, flowers sprinkled in grass, but grass in the flowers."

Muir was the first to well describe the pristine Great Valley's flowers but from early Spanish explorers to G. C. Merrifield in 1851 to the great California botanist Willis Lynn Jepson in 1925 others have told of once vast flower prairies in California's valleys. Many such accounts are compiled in Professor Richard Minnich's recent UC Press book California's Fading Wildflowers.

Muir often elegantly described the rapid loss of California's unique flower prairies, but they are far from all gone. Each spring the valley much as Muir saw it is present at Yolo County's Glide Tule Ranch as well as many other places.

Why then do many call places like the Tule Ranch "grasslands" when those seeing them first report few if any native grasses? Therein lies a tale.

Taxonomic botany straightforwardly describes (in Latin) new plants wherever they're found, but more theoretical plant ecology started in eastern colleges and then moved west to
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California. But the east is not like California. Its forests stretch continuously from Florida to Quebec except where people cleared them. Farther west in the drier Great Plains grassland is similarly nearly continuous from Mexico to Saskatchewan. But in California it's just a few steps from dark redwood forests to open prairies and Napa County has greater vegetational diversity than most eastern states.

There's a simple reason for this difference. In the east it rains when it's warm and plants grow fast, but in California it doesn't. Rain here falls when it's too cold to grow so it's stored until temperatures rise. Consequently soil where it's stored determines vegetation much more in California than in the east.

Water and air deeply penetrate sandy and rocky soils where plants with deep roots like shrubs and trees can reach them. Clay soils, in contrast, favor the shallower roots of herbs because they keep water near surfaces and exclude air.

Since water carries clay farther than sand and rocks, California valleys usually have more clay and thus prairie vegetation, but places streams carry sand and gravel into valleys like along Yolo County's Buckeye Creek have trees even where water is scarce.

Eastern plant ecologists used to continuous vegetation in absence of disturbance expected it also in California. Minnesota's W. S. Cooper thought this was chaparral and claimed it once covered the Central Valley. More influential was Frederick Clements of Nebraska's theory it was covered with a bunchgrass now called purple needlegrass. Clements made and believed grand theories.

In 1997 Jason Hamilton showed Clements' bunchgrass theory came from expectations about California derived from his Nebraska experience. Evidence for it was minimal and came from atypical valley places like Jepson Prairie, where moist sea breezes bring many coastal plants inland, and Fresno, where Kings Canyon glacial outwash carried much sand to the valley floor.

Clements and followers like L. Burcham and H. Heady popularized a legend that the Great Valley was a bunchgrass sea wiped out by grazing and drought in the 1860's and replaced by non-native annual grasses.

The legend's ultimate popularization came with calling the valley "grassland" in Munz & Keck's A California Flora, the source for plant identification from 1959 to 1993 before the new Jepson Manual replaced it.

Why not the legend? It's false for one thing. Muir, Merrifield and others in early California vouch for that. Secondly, so-called "native grass restoration," planting coast and foothill needlegrass in valleys where it's not native, wastes much time and money.

Cattle ranches mostly well use and protect prairies, but when sold for development planners almost universally call their vegetation "non-native grassland," which ignores native wildflowers (forbs) and privileges weeds. Consequently California Prairie, the name Burcham used clear back in 1957, was the only major California plant community systematically excluded from general plan conservation elements until recently.

Since calling prairie "non-native grassland" made it defenseless by emphasizing its weeds rather than its native forbs, it became the ideal place for planners to direct sprawl. It is as if riparian areas were called "Giant reed-saltcedar thickets." To protect something it must be named. That name is California Prairie.

-- Dr. Glen Holstein is a member of the Board of Directors of Tuleyome, as well as the Chapter Botanist for the Sacramento Valley Chapter of the California Native Plant Society. Prior Tuleyome Tales are available at www.tuleyome.org