Vegetation Types of San Elijo Lagoon

San Elijo Lagoon Vegetation Types

Click below to learn more about:

• Salt Marsh
• Freshwater/Brackish Marsh
• Salt Flat
• Coastal Dunes
• Coastal  Scrub
• Chaparral 
• Grassland/Herbs
• Riparian
• Woodland
• Non-native Vegetation

Salt Marsh

Saltmarsh vegetation occurs at the edge of the ocean where tides flood and drain shallow bays and estuaries. Plants of the salt marsh are adapted to high concentrations of salt, and they possess mechanisms to exclude or extrude salt. Saltmarsh plants must be adapted to changing water levels caused by the ebb and flow of the tides; species tend to be distributed according to the maximum depth and duration of inundation. Saltmarsh species are usually upright, non-woody plants such as grasses and succulents.

San Elijo Lagoon is an estuary, a drowned river valley that receives salt water at the lowest end and fresh water from Escondido Creek and La Orilla drainage at the eastern end. Our salt marsh extends from the inlet opening at the beach, to the upper end of the tidal action, near Santa Carina.

Typically in San Elijo Lagoon, California cord grass occupies the deepest zones, with pickleweed and salty susan above the cord grass, and salt grass and alkali heath nearest the trail.

Freshwater/Brackish Marsh

In a brackish marsh, the salinity varies between fresh and oceanic, often where a freshwater source, such as a river, meets ocean water. The vegetation is a mix of freshwater and saltmarsh species. An estuary often supports a brackish marsh near the upper end of the tidal influence.

Freshwater marshes occur beyond the reach of seawater.Freshwater vegetation is dominated by tall, grass-like plants such as cattails, rushes and bulrushes.

Most freshwater marshes in San Elijo Lagoon occur outside the Reserve, along Escondido Creek. 

The east end of San Elijo Lagoon is dominated by brackish marsh. Here, freshwater species such as southern cattails and California bulrush thrive next to areas of saltmarsh species such as pickleweed and saltgrass. Annual and interannual changes in environmental conditions, imposed on variable topography, often result in large patches and stripes of different species, swirled together in fanciful designs.

Salt Flat

Salt flats, or salt pans, develop in low areas where water accumulates, and subsequent evaporation leaves high concentrations of minerals on the surface of the soil. Plants are often restricted to the margins of salt flats, leaving much of the flat unvegetated. When flooded by winter rains, salt flats are often rich feeding areas for ducks and shorebirds.

In the Reserve, there are small salt flats in East Basin. The largest extends along the south side of Escondido Creek across from Mira Costa College. Our salt flats are often edged with slender-glasswort, a small, annual pickleweed that turns dark red during the summer months, neatly outlining the area.

Coastal Dunes

Coastal dunes occur at the margins of the ocean where wind and water constantly remove and redeposit sand, shaping it into ridges and mounds. Dune plants must survive salt and heat, draught and inundation and a constantly shifting substrate. They are generally prostrate herbs with creeping stems and extensive, fleshy roots; leaves are often pale from a dense cover of hairs.

Historically, the ocean front between Cardiff and Solana Beach was a system of active dunes. With development, the movement of sand was curtailed. West of Coast Highway, the sand eroded and was replaced by riprap to protect the road. Inactive dunes on the east were overgrown with non-native plants.  Beginning in the early 2000’s the sandy substrate was restored and both areas were replanted with typical dune plants. Once again the dunes are brightly colored by beach primrose, and beach sand verbena and harbor the rare coast woolly-heads.

Coastal dune vegetation is sometimes classified as a subtype of coastal strand vegetation (the narrow strip of vegetation that is directly influenced by its proximity to the ocean). An area on Harbaugh Seaside Trails has been planted to demonstrate coastal strand vegetation.

Coastal  Scrub

Plants of the coastal scrub (or coastal sage scrub) are adapted to long, dry summer months, growing rapidly during the rainy season and often becoming dormant or semi-dormant during summer and fall. They are typically drought-deciduous shrubs or sub-shrubs, less than 5 feet in height, with extensive but shallow root systems. Many plants of the coastal sage scrub are aromatic.

Coastal sage scrub is the most common vegetation along the trails of the San Elijo Reserve. Dominant plants include California sagebrush, coast buckwheat, black sage, and coast sunflower.

In California, coastal sage scrub has been subdivided into several types. The most abundant in the Reserve is Diegan sage scrub, the form described above. The other is maritime succulent scrub, characterized by a higher percentage of succulent species such as species of cactus, yucca, agave and dudleya. Two areas on Harbaugh Seaside Trails have been planted to demonstrate these two vegetation types of coastal sage scrub

Chaparral 

Chaparral is a dense growth of evergreen shrubs, three to ten feet high, with rigid, woody stems and small leathery leaves. Chaparral species can photosynthesize all year long, but maximum growth rates are low. Species in the chaparral are adapted to naturally occurring wildfires, either resprouting from underground burls, or germinating from seeds, many buried for years in the soil. Common chaparral species include chemise, species of manzanita, of mountain lilac and of scrub oak. Chaparral is widely distributed throughout California and has been subdivided into numerous types, two of which are found in San Elijo Lagoon Ecological Reserve.

In the Reserve,  southern maritime chaparral is prominent and often occurs along the hill tops. Dominant species include chamise, mission manzanita and wart-stemmed ceanothus. Southern maritime chaparral is planted in one area on Harbaugh Seaside Trails. Near the eastern end of the Reserve, scrub oak becomes dominant; this type of chaparral is called scrub oak-chaparral. 

Grassland/Herbs

As the name suggests, this vegetation is dominated by grasses and herbaceous plants, including some of our loveliest wildflowers. There are few or no shrubs or trees. Many of California’s original grasslands and flower fields have been eliminated by development or displaced by non-native annual grasses.

In the Reserve grass-and-herb dominated areas are found in openings of the sage scrub and chaparral and in areas formerly used for agriculture, such as Stonebridge Mesa. Today, these grassy areas support mostly non-native species, but recent revegetation projects attempt to introduce, or re-introduce some of our native species, especially native bunch grasses. Native wildflowers include goldenstars, soap plant, and blue-eyed grass.

Riparian

Riparian vegetation is found beside streams and lakes and other freshwater features that provide a reliable source of freshwater. Riparian species are often trees such as willows, cottonwoods, alders or sycamores, which are able to survive or regenerate after occasional heavy floods.

In San Elijo, riparian vegetation is found along Escondido Creek. Other areas are associated with runoff from surrounding developments. A lush area at the Nature Center marks the site of an old sewage treatment facility and fresh water is provided by runoff from the surrounding development. In San Elijo, riparian areas are dominated by small willows, primarily arroyo willow with associated taller trees such as Gooddings black willow, California sycamore, and Freemont’s cottonwood. Smaller shrubs such as mule fat and toyon are often at the outer edges, along with understory plants such as mugwort and yerba mansa.

Woodland

Woodland vegetation is dominated by large trees.

The only native woodland in the San Elijo Lagoon Ecologial Reserve is a cluster of Torrey pines in East Basin, below the Santa Helena trailhead. Other wooded areas here are dominated by non-native trees such as eucalyptus and acacia.

Non-native Vegetation

Non-native vegetation often thrives in disturbed areas. Invasive grasses and herbs move quickly into abandoned agricultural lands. Eucalyptus and acacia trees were deliberately planted for shade and shelter. Some plants come in from adjacent gardens, like the charming but aggressive nasturtium. Non-native species, whether introduced accidentally or for agricultural, medicinal or aesthetic reasons, come without their complement of native grazers, parasites and diseases with which they have evolved. This gives them a competitive advantage over our native plants while they do little to provide support for the other species of the native community.

In San Elijo Reserve non-native species often occur along the trails. Larger areas, such as old acacia and eucalyptus groves and old agricultural fields are slowly being restored to their native species.