The Santa Cruz Sandhills
Protecting Our Biological Treasure,
Water, and Endangered Salmonids in the
Santa Cruz Mountains
Text and images by Jodi M. McGraw © 2007.
R
ecognized as one of the rarest ecosystems in the United States, the Sandhills are a f a s c i n a t i n g b i o l o g i c a l c o m m u n i t y found only on outcrops of sand soil in central Santa Cruz County. The Sandhills support The Santa Cruz Sandhills
a wealth of native biodiversity, including at least four plants and three animals that occur nowhere else in the world. Like a jewel, the Sandhills are precious due to their uniqueness, rarity, and fragility. Uniqueness T
he story of the Sandhills began more than 10 million years ago, when a vast, shallow sea covered the Central Valley and emptied into the Pacific Ocean near Santa Cruz. Later, as the Santa Cruz Mountains formed, the sand that was deposited on the ancient sea floor was lifted up. Today, these sand deposits are found on ridges near the towns of Felton, Ben Lomond, Scotts Valley, and Bonny Doon. As evidence of their marine origins, the Sandhills con‐
tain fossils of sand dollars, sea cows, extinct sharks, and other ancient ocean species. Marine fossil from the Sandhills
Santa Cruz County features a moist, maritime climate that supports lush forests including Coast Redwood Forest, on the rich loam soils that dominate the region. However, the islands of sand soil create droughty and infertile condi‐
tions that require special adaptations for life. Sandhills plants must be able to tolerate the long summer drought, while Sandhills animals must be adapted to the sparse vegetation and summer temperatures that can exceed 100 degrees. The unique combination of sand soil and a moist climate lead to the evolution of at least seven species within the Sandhills (Box 1). Scientists have yet to describe all of the species endemic to (found only in) the Sandhills. As a result, the uniqueness of the Sandhills is a story that is yet to be fully written. Rarity T
he Santa Cruz Sandhills are extraordinarily rare. Found only in central Santa Cruz County, the Sandhills are estimated to have originally covered a mere 6,000 acres. Unfortu‐
nately, sand quarrying and development have removed more than 40% of the habitat, leaving Sandhills species to survive within less than 4,000 acres. By way of comparison, the Coast Redwood Forest—an ecosystem widely recog‐
nized as rare and endangered—covers more than two million acres, with an estimated 90,000 acres of old growth redwood forest remaining. Distribution of the Santa Cruz Sandhills
Box 1: The Known Endangered Sandhills Species
Zayante Band-Winged
Grasshopper (FE)
Mount Hermon June Beetle (FE)
Santa Cruz kangaroo rat
(listing package being prepared)
Santa Cruz Wallflower
(FE, CE, CNPS 1B)
Ben Lomond Spineflower
(FE, CNPS 1B)
Ben Lomond Buckwheat
(CNPS 1B)
Bonny Doon (Silverleaf)
Manzanita (CNPS 1B)
FE=Federally Endangered; CE=California Endangered; CNPS 1B=
California Native Plant Society Rare or Endangered
Fragility
T
Since 1984, the Santa Cruz Wallflower has been lost from six Sandhills sites, while the Santa Cruz Kangaroo Rat has disappeared from four of its five historical locations. These extirpations have lead to serious concern that additional Sandhills species will go the way of the Greater Roadrun‐
ner. Not known to occur elsewhere in Santa Cruz County, this unique bird oc‐
cupied the Sandhills until 1964 after which habitat loss and deg‐
radation ultimately Quarry in the Sandhills
lead to its extirpation. The Importance of the Sandhills for Water, Stream, and Endangered Salmonid Conservation I
n addition to its extraordinary biotic value, the Sandhills ecosystem plays an important role in protecting the quantity and quality of our drinking water, and maintaining the fragile river‐
ine systems of the San Lorenzo River Watershed. The Sandhills occur on the Santa Margarita Aq‐
he biological communities of the Sandhills uifer—an underground porous sandstone forma‐
are critically endangered. Development has tion that bears groundwater. Rain that falls on fragmented much of the remaining habitat, pre‐
the coarse Sandhills soil percolates into the aqui‐
venting plants and animals from migrating, and fer, where the San Lorenzo Water District has lo‐
thereby threatening persistence of their dwin‐
cated many well that provide an estimated 18,500 dling populations. people in central Santa Cruz County with 50% of Sandhills habitat is being degraded by exotic their water each year. Development of Sandhills plants, which crowd out native plants and render habitat reduces water percolation into the aqui‐
habitat unsuitable for native animals. Due to the fer, reducing its water level. Meanwhile septic erosive nature of Sandhills soils, recreation tanks, pesticides, and other pollutants associated causes extensive erosion. Sandhills habitat is also with development can contaminate the aquifer. being degraded by the exclusion of natural wild‐ Preservation of Sandhills habitat protects the fires, which is reducing the open habitat required quantity and quality of water for people in cen‐
tral Santa Cruz County. by several of the endangered species. Preservation H
abitat preservation is essential to conserv‐
ing the endangered Sandhills species and communities, and protecting the groundwater, streams, and rare salmonids in central Santa Cruz County. To facilitate preservation, the highest priority parcels for conservation of the endan‐
gered Sandhills ecosystem have been identified in a Conceptual Area Protection Plan for the Santa Cruz Sandhills. Water Facilities in the Sandhills
Preservation of these areas will require collabora‐
tion among federal, state, and local agencies and Conservation of the Sandhills ecosystem also organizations. Only through such efforts will we be protects stream habitat within the San Lorenzo able to preserve this extraordinary legacy that has River Watershed. Rather than holding water for been entrusted to us. long periods of time, the Santa Margarita Aquifer feeds the streams within the watershed, includ‐
ing the San Lorenzo River and its tributaries, Newell Creek, Bean Creek, and Zayante Creek. These streams support rare salmonid popula‐
tions, including the threatened Central Coast evolutionary significant unit of steelhead trout and one of the southern‐most runs of the endan‐
gered coho salmon. Water diversions from the San Lorenzo River for the City of Santa Cruz have caused low summer flows that threaten these fish and other Spring wildflowers in the Santa Cruz Sandhills
aquatic species. Per‐
colation of winter For further information about efforts to preserve rainfall into the Santa the Santa Cruz Sandhills, please contact: Margarita Aquifer Terry Corwin from intact Sandhills Executive Director habitat helps main‐
Land Trust of Santa Cruz County tain flows during the 617 Water Street summer drought. In Santa Cruz, CA 95060 contrast, develop‐
(831) 429‐6116 ment in the Sandhills [email protected] increases run‐off, rob‐
bing the aquifer and streams of important For more information about the Sandhills, go to Bean Creek,
www.santacruzsandhills.com summer water. a steelhead stream