Habitats
Habitats at Ballona are a complex mosaic resulting from many years of floodplain alteration and filling of
the historical wetlands, yet many native species and communities still thrive. As mapped by the Coastal
Conservancy today, habitats at Ballona are defined mainly by hydrology, i.e. whether the habitat is
estuarine, freshwater, seasonally flooded, riparian, or upland. Many wildlife species, especially birds,
utilize more than one habitat type – thus the juxtaposition of these habitats next to one another is
important for biodiversity.
Estuarine and Brackish Marshes
Estuarine marsh is limited to the western half of Area B, south of Ballona Creek. Currently, species
diversity is lower than would be found in an undisturbed estuary, with pickleweed (a high marsh
species) by far the dominant and most recognizable salt marsh plant. This low diversity is due to
restricted tidal influence, a condition that will change when restoration plans are implemented. Narrow
tidal channels, which are artifacts of past disturbance and attempts to drain the marshes, affect the
distribution of estuarine habitat. Above and away from the tidal channels are salt pans. Salt pans are
relatively flat depressions which can be flooded with salt water during high tides, or become ponds
during the rainy season. Salts in the clay soil leach out to the surface, and over time these salts
accumulate, leading to exceptional saline conditions when water is present. Hundreds of birds can be
seen flocking to these salt pans when ponds have formed after rains or high tides.
Inland from the estuary, in the southeast corner of Area B near the Freshwater Marsh, are pockets of
small brackish marshes. These small marshes have salty clay soil but receive their water from rainfall.
Historically, brackish marshes were probably extensive at Ballona, existing where unchannelized Ballona
and Centinela Creeks entered the salt marsh. With restoration it is expected that the extent of brackish
marsh will expand, and this habitat will once again become a significant component of the Ballona
ecosystem.
Freshwater Marsh and Riparian Habitats
The Freshwater Marsh is located southwest of the intersection of Lincoln and Jefferson Boulevards,
adjacent to the Ecological Reserve. Apart from riparian, this constructed wetland is currently the only
major freshwater habitat at Ballona, representing a small fraction of a much more extensive freshwater
wetland that existed historically before Ballona and Centinela Creeks were channelized. Since
construction was completed in 2003, the habitat has attracted more than 200 species of birds, some of
which are now returning every year to nest after more than a 70-year absence.
Riparian habitat is defined by a freshwater stream or presence of fresh groundwater within reach of
plant roots. Riparian habitat at Ballona consists of a meandering corridor along the base of the
Westchester Bluffs and the south edge of the Ecological Reserve. This habitat represents a small
fraction of what must have been present before Centinela and Ballona Creeks were channelized.
Historical records show the riparian habitat dominated by alder trees. Currently, most of the riparian
habitat consists of willows. Diversity increased with construction of a riparian channel east of Lincoln
Boulevard. While this channel is outside of the Ecological Reserve, its diversity of planted native riparian
species is expected to attract many of the wildlife species that were present historically at Ballona.
Seasonal Wetlands
Currently, seasonal wetlands at Ballona are artifacts of past human disturbance. These wetlands are in
areas that are isolated from stream or tide influence because they are too high in elevation or have
been cut off from natural surface water sources. These wetlands have formed in small depressions and
depend entirely on rainfall as a source of water. Due to soil salinity, pickleweed (normally a salt marsh
plant) tends to dominate these wetlands.
Uplands
The Coastal Conservancy’s habitat map is limited to the Ecological Reserve. Adjacent to (and south of)
the Ecological Reserve is an important upland habitat called coastal sage scrub, along the face of the
Westchester Bluffs. Another important upland native habitat at Ballona is the Dunes, located on the
west side of Area B. The Dunes have been a major focus of restoration by the Friends of Ballona
Wetlands. Elsewhere within the Ecological Reserve, most upland areas have been invaded by nonnative species and do not fit any standard habitat classification. Management and control of these nonnative species, and their replacement with native habitat, will be one of the goals of restoration.