Riparian
Riparian zones are the outliers in the mostly dry Burton Mesa Ecological Reserve. Burton Mesa is a marine terrace topped by giant sand dunes.
A short geological digression:
The Santa Ynez block has been pushing northwards for the 20 million years, carried by the Pacific Plate. It contains the the Santa Ynez Mountains and its northern boundary is the hills just south of Lompoc. Northward pressure in the last few million years cause the land to fold and raise the Purisima Hills, just to the north of BMER, above the ocean floor. During a lull in this elevation a flat marine terrace formed by erosion. Prevailng north and west winds carried fine sand that dropped in the lee of the Purisima Hills, forming Burton Mesa. Little grains of quartz don't hold moisture, so most rainfall trickles down until stopped by the impermeable rocks of the oilfield. The dry dunes encouraged the development of chaparral and scrub plant communities. It also creates a perched water table that slowly leaks through canyons to reach the Santa Ynez River a few miles away.
I see three distinct riparian types:
- Hidden Lake — less than a mile north of Cabrillo High School. Hundreds of yards wide, the northern end has filled with cattails and tules. It hosts hundreds of migrating waterfowl in the winter (coots, mallards, ruddy ducks) and remains full during the summer drought.
- Marsh and stream — at Burton Mesa and Clubhouse. Davis Creek starts near a reservoir on the Mission Club, augmented by irrigation runoff from golf and surrounding homes. It broadens into a marsh above Burton Mesa Road as it crosses the Davis Canyon. A culvert releases water below Burton Mesa Road, continuing to the Santa Ynez River and the ocean.
- Vernal pools — fed by winter rains. Some surface depressions become less permeable and form large puddles through the rainy season. My housmate Kevin, a biology student from UCSB, drove here frequently to study toads in these pools.
The indigenous Chumash probably treasured these fresh water sources. But the plants were crucial to their culture.
- Habitat — they wove long leaves into into dome-shaped structures called 'ap
- Food — starchy roots pounded into flour, young shoots used like asparagus, young flowers might be eaten or pollen turned into mush
- Crafts — Leaves woven into mats and baskets
- Medicine — roots and pollen used for home cures
- Canoes — Woven tules could be sealed with tar from petroleum seeps, they crossed the Santa Barbara Channel and inhabited the islands
Lake
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Stream
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Marsh
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Vernal Pool
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