The official website of the Elkhorn Slough Foundation and Elkhorn Slough National Estuarine Research Reserve
Slough Speak: A glossary of slough terms
Cows at Porter Ranch
Used in a planned disturbance regime, cattle, like these on Porter Ranch,
can help native plants thrive and reduce invasive non-natives.

Charismatic megafauna: A term used to refer to large and appealing animals, e.g. otters, egrets, whales. Environmental groups often feature "charismatic megafauna" in their materials because, well, they're more appealing to people than what some might call "repulsive microfauna."

Conservation easement: A legal agreement between a landowner and a land trust or government agency that permanently protects land while the landowner continues to own it. Donating the easement can result in reduced inome or estate taxes. More than 17,000 conservation easements protect 4.7 million acres of land in the United States.

Degraded or disturbed soils: Soils that have been altered by human activity, which makes them less capable of supporting native plant communities and sometimes more susceptible to non-native invasion. In the Elkhorn Slough watershed, the dominant forms of disturbance are the cultivation of steep slopes, erosion, and overgrazing.

Disturbance regime: The disturbance of the soil and plant communities in ways that are natural or mimic natural disturbance and thus foster healthy ecological conditions. The grazing of cattle at the Porter Ranch is an example of a disturbance regime designed to mimic the grazing patterns of wild herds and thus benefit native bunch grasses and grassland-dependant species such as badgers, gopher snakes, white-tailed kites, western bluebirds, bobcats, and burrowing owls.

Ecotone: The transition zone between communities, such as between uplands and wetlands. These transitional areas can be unusually rich in flora and fauna, with elements from both of the adjoining communities.

Elkhorn Highlands: The sandy hills lying to the east of Elkhorn Slough. Because these hills drain into the slough, what happens on them is vital to the health of the slough. The upper ridges of these hills are covered with maritime chaparral, a rare plant community in California.

Endangered or threatened species: A plant or animal species facing the danger or threat of extinction. The state and federal governments have separate lists of "endangered" or "threatened" species. An endangered species is one already facing the danger of extinction. A threatened species is one that is likely to become so in the foreseeable future. Endangered or threatened designation makes it illegal to "take" a species, a term which includes harassment or making significant modification to its habitat. Endangered animals enjoy significantly more protection than plants. Some of the endangered or threatened species in the Elkhorn Slough watershed include: Western Snowy Plover, California Sea Otter, Monterey Spineflower, and Santa Cruz Tarplant. (Brown Pelican populations have recovered enough that on December 17, 2009 they were de-listed as an endangered species.)

A curlew in the pickleweed, no doubt looking for
invertebrates, not far from the ecotone that can be
protected by good furrow alignment.

Erosion: The wearing away by, or as if by, abrasion. Soil erosion in the Elkhorn Slough watershed occurs most dramatically on steep sandy slopes where disturbance leaves the soils exposed. The worst soil erosion west of the Mississippi has been measured on slopes in this area. The 1999 Elkhorn Slough Watershed Conservation Plan identifies erosion and sediment runoff as “the most serious threat” to the ecosystem.

Fallow ag: Farm land not currently in cultivation. ESF has acquired 271 acres of fallow agricultural land this year, almost all of it on steep slopes not suitable for sustainable, environmentally sensitive farming. Such lands could also be called "restorable hillsides," because that is what we will do with them.

Furrow alignment: A furrow is the shallow trench between rows of crops. Furrows aligned running up and down a slope increase water runoff and soil erosion. Furrow alignment that cuts across the slope, following the contours, reduces runoff and erosion.

Holistic grazing: Planned grazing that attempts to mimic natural grazing patterns by varying the intensity, duration, and frequency of grazing – with the desired result being healthier grasslands.

Invasive non-native: A plant that did not evolve in a particular region but aggressively grows there, altering natural processes and crowding out native plants.

Invasive species: A non-natime species of plant or animal that crowds out the native species. Only 10% of non-native species are considered invasive. In the Elkhorn Slough watershed, pampas grass (jubata grass) is particularly threatening to the maritime chaparral plant community.

Invertebrate: An animal lacking a spinal column. There are more than 550 species of marine invertebrates (clams, shrimp, crabs, worms) in Elkhorn Slough, including the Fat Innkeeper Worm, world famous among biologists as a zoological oddity.

Land trust: A nonprofit organization that actively works to conserve land by undertaking or assisting in land or conservation easement acquisition, or by its stewardship of such land or easements. The 1500 land trusts in the U.S. have protected 9.4 million acres of land.

Linkage: Interconnection. ESF uses the term to refer to the stitching together of parcels of land to create large blocks that will help sustain a greater diversity of species. Some animals, like bobcats, need the considerable room to roam that can be provided by linked lands.

Maritime chaparral: A rare plant community that occurs within the central California coastal zone. The California Native Plant Society has designated over a dozen species in this habitat as "species of concern." The plants of this community require cool, foggy summers and well-drained, sandy soils. Maritime chaparral occurs on the ridges and south-facing slopes in the Elkhorn Highlands. At one time maritime chaparral covered extensive areas in the Elkhorn watershed. During the past forty years many south-facing chaparral slopes were converted to agriculture and housing. At the present time there are 1700 acres of maritime chaparral in the 45,000-acre Elkhorn Slough watershed.

Native bunch grass: Generally, the perennial grasses which have grown here for tens of thousands of years. Native grass grows in clumps or bunches, providing a rich habitat for animals and wildflowers. Imported European grasses are more evenly spread, choking out native wildflowers and providing a less hospitable habitat for small animals. Elkhorn Slough's best stand of native bunch grasses is on the Porter Preserve. ESF has extensively planted native bunch grass at Azevedo and Blohm Ranches.

Native plants: Plants which evolved in and grow naturally in a specific region.

Habitats restored with native bunch grasses are ideal
for raptors like this red-shouldered hawk.

Northern Crescent: The term used in the Elkhorn Slough Watershed Conservation Plan to describe the hills running east and northeast of Elkhorn Slough. These hills were identified as a top priority for protection both because soil erosion from farming on steep slopes was a major threat to the slough, and because the small number of relatively large parcels made acquisition feasible.

Pickleweed: Salicornia virginica is the dominant plant in the salt marshes of Elkhorn Slough. It is green throughout the summer and turns red in the fall.

Protected Land: We call land “protected” when its future use is legally restricted to protect its natural resource values. Land can be protected when it is acquired by a land trust, or by entering into a preservation agreement between a land trust and a private owner. Most of the 3600 acres protected by the Foundation is land we have acquired, but in some cases (Triple M Ranch, for example), the land is owned by others with a preservation agreement held by ESF that protects the land from certain uses.

Raptor: A bird of prey, characterized by a hooked bill and strong talons. Raptors commonly found in the slough watershed include White-Tailed kites, Northern Harriers, and Red-shouldered and Red-tailed Hawks.

Restore: To bring back into existence or use, to return to original condition. Restoring land in the Elkhorn Slough watershed means planting native vegetation, opening up streams and ponds filled with eroded soil, returning the land to its natural ecological complexity as a habitat for animals and plants.

Riparian corridor: The bank of a natural course of water, home to a wide variety of reeds, bushes, trees and animals, the natural route for the watershed's drainage. The Elkhorn Slough watershed has 1200 acres of riparian corridor, including Carneros Creek which supplies 70% of the slough's fresh water. The Elkhorn Slough Foundation protects 1600 acres of land which drain into Carneros Creek.

Sediment basin: A small dam which catches runoff water, allowing soil to settle to the bottom and cleaner water to flow into a nearby waterway, thereby reducing soil runoff. Later the sediment is removed from the basin.

Tidal barriers: Barriers that partially or fully limit the flow of tide waters, such as levees, dikes, road or railroad beds, and tide gates. By the 1950s more than 37 miles of tidal barriers had been built in and around Elkhorn Slough, reducing tidal flow to more than half the former marsh lands of Elkhorn Slough. Today many of these barriers have failed or been removed.

Snowy Egret
By protecting wetlands from soil erosion, ESF is also
protecting habitat for birds like this Snowy Egret.

Tidal erosion: The process by which tidal flows erode banks and channel beds, sometimes called tidal scour. The average rate of bank erosion along the slough's main channel is twenty inches a year in the upper slough and twelve inches a year in the lower slough. The average width of tidal creeks has increased from eight feet to over forty feet in the last 70 years.

Tidal volume: The volume of sea water that comes on a tide. The tidal volume of Elkhorn Slough has doubled since 1970. Increased tidal volume and current velocity lead to a wider and deeper channel, which, in turn, increases tidal volume.

Watershed: 1) The region draining into a body of water. The Elkhorn Slough watershed comprises 45,000 acres, from the Parajo Valley south to Castroville, and from Monterey Bay east into San Benito County. 2) A critical point that serves as a dividing line. In 2002 the Elkhorn Slough Foundation announced that it would double the amount of land it protects – a watershed moment for the watershed.

Wetland: Alow-lying area that is saturated with water, including tidal canals and mudflats, as well as freshwater, brackish, and saltwater marshes. The wetlands of Moro Cojo Slough include coastal salt marsh, alkali grasslands, freshwater marsh, and freshwater herbaceous wetlands. Wetlands provide critical habitat for a variety of plant and animal species, including more than half of California’s threatened or endangered species.

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This site is maintained by the Elkhorn Slough Foundation in partnership with the Elkhorn Slough National Estuarine Research Reserve